maybe you are misjudging their play. It is easy to play"like a master" if your oppenent makes a really bad mistake or has a really bad position .
Ratings seems to be meaningless
Sort:
because the 1200 player are pro in tactic, and its a tactic on the board that the 1700 player would miss
A rating may sometimes correlate more closely to the thing it is rating than things it is not. 
what about this player, a friend of mine OTB:
http://www.chess.com/members/view/mathias94
Standard below 1200, blitz and bullet below 900, online chess 1600, Tactics: 2100+.
May 30, 2015
0
#6
see my blitz rating played only 5mts and ten mnts..games ..first 10 games
were lost by me as i was unfamiliar with the site and not knowing the rules..then secondly I learnt that in blitz games u have to be able to pass
ur time appropriately in making the moves in time and let ur opponent falter in time and u win..
live std chess is some thing u can count on ur actual chess abilities..
but here too when bug problem or browser problem i don't know
not able to see the pieces on board hence dropped fm 1682 to 1593 in
abt 10 games and i left both these ..1 month with blitz and abt 2 months
with live std chess..then i switched to on line chess and here i am ..
progress slow but study for last five months ..fm 1500 to 1700 only
advanced ..because the win in first 4 games got me past the 1500 mark ..
as explained by me now u know why it happened..not due to some other
reasons..(i mean the diff. in rating of diff.categories)..
if ratings were pointless then they would change more frequently
agreed
then why are he 2100+ in tactics?
also My tactics rating on chess.com is 2400+ so...... maybe chess.com is not the best site for tactics.
whats your fide rating?
1985
Ratings aren't meaningless. They just don't mean as much as most chess players like to think.
The board is what matters in 1 game in 1000 games rating is what matters.
May 30, 2015
0
#15
Bad internet connection: -100 rate
Distraction's playing blitz: -100 rate
Not giving half the effort or being risky: -100 rate
Misclicking alot : -100 rate.
Etc...
Well, in summary, it can depend on a lot of things while playing online and fast. Blitz hardly measures a playings strenght OTB tbh, except for master level and above.
Go play OTB. You will see that 1100 rated players are probably like 1800 online. Not even kidding.
May 30, 2015
0
#19
My trainer always told me "ratings mean everything to people" he also always told me that they are meaningless. I have always refused to believe in ratings because they are not always as accurate as people think. That said, one must have a high rating to be appreciated as chess.com users have a terrible habit of judging by rating instead of play. This means one must not just dismiss ratings but accept them for what they are: a necessary evil. With ratings we may judge poorly, but without them we are totally lost.
Feb 14, 2022
0
#20
If you are a beginner on this site, ratings are indeed random. You'll fluctuate 300-500 points regularly, and often play games that feel like you are playing masters or even computers, while others will be on your level.
We're not allowed to talk about the reasons this is the case on these forums, so just resolve to not caring, wait until pandemic is over and play OTB instead then.
If you think about the mathematics of how a small number of people can totally remove information from the ratings system with bad behavior (we can actually fix this with good mechanism design, but no one is listening or caring), you'll see that ratings are indeed meaningless - esp. at the bottom end / beginner level - where the actual math makes it worse and eliminating the bad behavior is nigh impossible.
Sometimes a player who is below 1200 demonstrates the skills of a master and sometimes 1700 shows how ignorance prevails the world.
I would never be smart enough to understand these prevailing diversities.
Who cares except me?