Some people do not like to play unorthox openings. They prefer to steer the game into openings that they have studied. I don't know if that is the "only" reason for this behavior.
Can anyone figure this out?

Some players get annoyed when they see something as relatively common as the Modern Defense. Others may believe that they are being mocked or not taken seriously by things that are more unorthodox.
Firstly, in both of the cases I mentioned, I was playing White, so my opponents could have chosen whatever defense they wanted. Secondly, I had sent a short, friendly greeting to them both with my first move.
Maybe this isn't common knowledge, but there are actually two players during a chess game.
No need to be condescending!
No player can force the other to .... cooperate with some tactic they want to pull off, or blunder just because it makes for a more desirable experience.
Just what kind of "tactic" are we talking about after only 2 or 3 moves?!
As for a blunder - how many opponents have you played who blundered on their 3rd move?
Thanks for the input, but I think there has to be some other explanation...

Having it happen twice is a little odd, to be sure, but there's always a chance life intervened. Kid got hurt, stove exploded, whatever. I agree with your analysis that there isn't any logic behind the abrupt endings, so I'd think maybe the reason was something other than chess.
--Cystem

Unorthodox?? Would you call 1e4,e5 2f3 unorthodox?
Yes, very. It's hardly ever played, I don't think it's because it terrifies opponents into resigning, generally.

...for whatever the reason...it is clear you have done anything wrong...forget it...move on...don't let bug you...don't let it stress you ( otherwise your opponent has really won...by driving you crasy).
All the best...

forget it...move on...don't let bug you...don't let it stress you ( otherwise your opponent has really won...by driving you crasy).
Good advice - thanks.

Having it happen twice is a little odd, to be sure, but there's always a chance life intervened. Kid got hurt, stove exploded, whatever. I agree with your analysis that there isn't any logic behind the abrupt endings, so I'd think maybe the reason was something other than chess.
I agree with that, and I think I now know what it's all about - but I'd rather not get into it.
Thanks all for your comments!

Unorthodox?? Would you call 1e4,e5 2f3 unorthodox?
yea i think just about any player would call that unorthodox, i dont think it even has a name... maybe the rubygabbi anti-positional gambit? i never answer 1.e4 with e5 but if i did and my opponenet played 2.f3? i would clap my hands and squeal like a little girl! it kind of goes against general opening principles that have been around for a few hundred years...try 2.nf3, 2.f4, 2.d4, 2.nc3, or 2.bc4...general rules to follow develop toward the center, dont make unecessary pawn moves (like 2.f3), knights develop before bishops, try to castle early, dont move you queen to early, dont hunt down material at the expense of development, dont move the same piece twice, and know when to break the rules. as for your question, i think people sign up to be greeters then decied they dont want to be a greeter, and the other guy just didnt want to play...dont stress about it just find other opponents and move on.

Some players might see an opponent play 1. e4 e5; 2. f3, and think to himself "Oh god I don't want a game with a beginner," and run off.

Actually, this opening has two names, one of which can partly explain why your opponents left the game. "1. e4 e5; 2. f3" is the mighty King's Head Opening [C20], also known as the Patzer Opening.
ChessBase even knows of a GM game with this opening which resulted in a draw. However, ChessBase also knows that 70% of the games played with this opening resulted in a win for black.

I'm so very sorry - I owe all of you a heartfelt apology.
I just realized I wrote my third move as f3 when in fact I played Nf3. Now I understand your reactions! Sorry!
Two days ago I initiated an Online game, and was matched with someone instantly as White.
Had he not wanted to play for any reason, he could have, of course aborted the match immediately, but responded to my e4 with e5.
I then played f3, and he resigned!
Why would anyone want to do that?
This is the second time within a month that something like this has happened. My first online game was with a "greeter," who started playing, but after a grand total of two moves, refused to continue and lost by time forfeit. BTW, I know for sure he was online at various times up till the forfeit.
I sent messages to both players but received a reply from neither.
Has anyone had a similar experience? Can anyone suggest an explanation?

My "greeter" never showed up at all. He just timed out before the first move. It looked like a non-existent account was assigned to greet me-- no games on record at all. Not exactly a red-carpet reception!
--Cystem
Two days ago I initiated an Online game, and was matched with someone instantly as White.
Had he not wanted to play for any reason, he could have, of course aborted the match immediately, but responded to my e4 with e5.
I then played f3, and he resigned!
Why would anyone want to do that?
This is the second time within a month that something like this has happened. My first online game was with a "greeter," who started playing, but after a grand total of two moves, refused to continue and lost by time forfeit. BTW, I know for sure he was online at various times up till the forfeit.
I sent messages to both players but received a reply from neither.
Has anyone had a similar experience? Can anyone suggest an explanation?