The obvious reason is that it's neither practical, nor is it a good use of resources to enforce it.
It's not unreasonable to expect that chess.com will follow FIDE and USCF laws whenevery they are applicable and reasonably enforcable, but it is unreasonable to demand it when they are not.
Also, to expand on Cystem_Phailure's post #49, RetGuvvie98 was clear in his post to make the distinction that he was referring to those rules that govern behaviour, in apparent distinction to gameplay.
When reading the chess.com rules, it's easy for everyone who is acquainted to FIDE laws of chess to see that here on Chess.com, we only have a part of the rules written in the article.
It does not say that FIDE laws of chess does not apply, in-fact I for a fact know that some laws of chess, even if not written here applies.
I'll make an example, some of us often see a discussion regarding the "pinned piece can attack". If you look at the chess.com article describing the rules, you will only find a part "you can not put your king in check". But to make a whole package, the regulations from articles 3.1. and 3.9. FIDE laws of chess is missing in the chess.com rules. But anyone who played several games here knows that, even though this is not written in chess.com rules applies, so yes, pinned piece can attack.
It also doesn't say that the rules of Golf do not apply -- same for the rules of Baseball.
Should I assume that I must adhere to these as well?
So what? No one said none of the FIDE rules apply. It is correct to say that FIDE rules do not apply as long as their official rules are not the ruling source for all situations. And you guys have already identified a FIDE rule (nuisance draws) that is not in effect on chess.com, and of course there are others. What does not exist is any statement anywhere on chess.com saying FIDE rules are applied in their entirety. Repeatedly capitalizing "Laws of Chess" doesn't grant a status of universal truth for all of the conduct rules in all situations.
EDIT: this was in response to post #52-- the others snuck in! 
it is a little tough to "prove a negative" dragec. it should be really easy for you (or Fezzik) to prove a positive.
Would either of you please provide a reference - url or post by staff member - on this site, where the management states that they will follow all FIDE or USCF rules.
I have looked and did not find any.
nor did I find any rule stating that "User's reasonable expectations must be upheld by this site." (other than somewhat unsubstantiated allegations in this forum for instance).
Stating an opinion is not the same as stating a fact, and facts can be referenced easily. I'm not attacking the poster, merely stating that the opinions should be supported by references - if in truth they are valid. otherwise, they remain opinions.
I am NOT attacking you or Fezzik in this, only the allegation that FIDE rules have to be followed on this site (or the insinuation that they can be enforced on the internet - when the FIDE rules were written for and are typically implemented on OTB play).
What any other site does is their business, and this site is not obligated to follow any other site's procedures.
posted as a user only.
I made an example with pin.
But if there is not enough evidence(as here), both persons could claim to be right. Looking at some threads where Erik jumped in (mostly about so called "insufficient material" in live chess), he never said that chess.com is following some other rules, he only made a correct remark that due to a limited resources, chess.com can not have a tournament directors, nor a persons who can adjudicate a games, or checking if software failed to see a blocked position (dead draw). This all sounded very reasonable for me.
While I do not want to pursue the debate on who is right, I believe that "this is private site" expression doesn't mean that laws of chess should not be followed wherever reasonably possible.
In fact, if it really would be a case that someone would like to enforce his rules just for fun, chances are that the site would lose much of its members. Just my opinion.
So what? No one said none of the FIDE rules apply. It is correct to say that FIDE rules do not apply as long as their official rules are not the ruling source for all situations. And you guys have already identified a FIDE rule (nuisance draws) that is not in effect on chess.com, and of course there are others. What does not exist is any statement anywhere on chess.com saying FIDE rules are applied in their entirety. Repeatedly capitalizing "Laws of Chess" doesn't grant a status of universal truth for all of the conduct rules in all situations.
EDIT: this was in response to post #52-- the others snuck in!
There is (IMO) also no written statement that FIDE does not apply. It is empirically confirmed that some FIDE laws are followed here and some are not. But my personal explanation would be that those laws that are not followed, are not followed because it would be difficult to enforce it, not because Erik does not like the rule. Peace.
It also doesn't say that the rules of Golf do not apply -- same for the rules of Baseball.
Should I assume that I must adhere to these as well?
If you think it's necessary. Also a handball rules would be handy.
Clearly, the rules that require the presence of a human arbiteur to be enforced don't apply. This rule appears to be one such case.
There are other rules that don't apply for technical reasons such as the rules concerning making illegal moves (which is prevented by the interface), observing flag fall (the interface does this for the players) etc.
Also, if you look at FIDE handbook:
http://www.fide.com/component/handbook/?id=124&view=article
Articles 1-5 are classified under "Basic rules of chess", while the rest are classified under "Competition rules." It doesn't seem that the FIDE is expecting the Competition rules to be followed in any chess-playing venue.
insufficient material rules is not the FIDE rules, it is the way the game is played according to standard accepted procedures. erik has the rules of play for the game activities on the board of play.... but i am not seeing anything about behavior rules for 'during the game' other than not harrassing another user...
specifically, dragec, since Fezzik cited a FIDE Rule, and you appear to want to support him in that; I asked if you or Fezzik can cite a place on this site (other than your and his allegations) that FIDE Rules apply to this site. more to the point of the OP, where does it state that behavior rules for this site are governed by FIDE Rules ? (other than your allegations and Fezzik's somewhat vague references to "user expectations" that is.)
posted as an inquiring user.
I know that "insufficient material" is not a part of FIDE laws of chess, that's why i said "so called" and cited the expression. The term is often used in casual play and by people who usually do not know the FIDE laws of chess too well.
I already explained that I don't have a link that says "FIDE Rules apply to this site", and as an inquiring user I would like to ask you if you have a link saying "FIDE Rules does not apply to this site".
What some of us wanted to say is that it's reasonable to assume that as a chess site, chess.com would follow FIDE laws of chess where its practical to do so.
Atos noted some nice exceptions where from practical reasons chess.com have it implemented differently.
But, it's still far from "my site my rule" laws that you implying to be in place. It can be true though, but I hope it's not.
btw, the thread is successfully hijacked.
btw, the thread is successfully hijacked.
Hijacked? not even close. Entirely too "On topic" for my tastes. I'll come back later, when things have degenerated a little.
"1.3 If the position is such that neither player can possibly checkmate, the game is drawn."
That seems to cover insufficient material.
Also, if you look at FIDE handbook:
http://www.fide.com/component/handbook/?id=124&view=article
Articles 1-5 are classified under "Basic rules of chess", while the rest are classified under "Competition rules." It doesn't seem that the FIDE is expecting the Competition rules to be followed in any chess-playing venue.
even if it is a chess.com ' Tournament 'which I assumed WAS a ' Competition '..
So, no one has any evidence, except for empirical one.
All I have learned from this little exercise is what I already know (but it's good to repeat it), and that's , whats reasonable/normal/standard for one person doesn't necessarily mean that it's the same for other persons.
So it appears that we have a different expectations from chess.com, and there's nothing wrong with that.
Peace.
Regarding how to implement the multiple draw offer rule, that's dead easy. Either disable the draw offer button after 3 uses, or send an automated warning to the issuer if they hit the draw offer more than three times. If they continue to hit the draw offer, the player could even be auto-forfeited. But it would be easier to disable the draw offer button after 3 tries.
This seems like a sensible proposal, but note that this is not exactly the same as enforcing the FIDE rule. The latter would seem to require adjudicating as to whether the draw offer is "reasonable." For all we know, it might be. But again, this is a sensible proposal for a website.
The members of the site have a reasonable expectation that the Laws of Chess will be followed. The burden is on the site to explain any deviations from the Laws of Chess that are not due to the nature of online chess.
I think that determining whether a draw offer is "reasonable" or not would require the involvement of an arbiteur, which is typically not feasible in online chess.
In your practice as an arbiteur, did you have a case when someone was actually penalized for making an unreasonable draw offer ?