Do most GM games end in resignation?

Nope, this is just my imagination right now.

What is he missing?

 He is missing lessons in humility ....

I say this very jokingly (because at a high level these types of barely lost positions can be resignable most likely), but it seems like the GM's just baby each other you know? I mean they just lose the tiniest thing and right away they often just resign, and if they don't on some rare occasions I'm sure the winning GM would give some dirty looks. I only wish people would give me that respect in my games lol! My wins would be easy.

And another thing about GM's that I can't help but notice. If there's one problem in their game it's giving back material too much! Often one side plays a weird positional sac and the GM on the other side just gets scared and gives the material right back. One time on ICC they were actually showing grandmaster games live, and GM Nakamura made an insane (and in my opinion bad, I couldn't believe he did it) queen sac for only two pieces. GM Ehlvest gave back the material to clear things up and lets just say the computer did not agree! Counterplay is something you want to prevent, but you can't be terrified by it!

Ok that's stereotypical but I've seen a lot of games like that.

I think that's too harsh, I don't see any arrogance in the post. I have seen GMs resign in totally obscure positions to me, but I also have seen them resign when the forced mate was close, I remember Morozevich vs Kramnik from the last time they played. London or Tal, I'm not sure. Or Topalov vs Kamsky when Kamsky threw away his chances for the title, he just "couldn't" resign even if he was serious material down. It happens in GM play.

I'm really not trying to be arrogant, I'm just letting out what has been on my mind about the mysteries of grandmaster chess (as well as the new etiquette on when to resign!). It really is like a whole new planet that I'm attmepting to understand. I'm sure many times when they return material it's the correct thing to do, but I also think it's their human nature to want to stop counterplay, making return sacs extremely tempting to them.

Resignation probably because they can see quite a bit of moves ahead, and there would be no purpose for them to play them through

You should resign when you know you are lost.  At the very beginning this can even mean making some kid play out a rook versus king ending.  What is resignable changes with skill.  I certainly would make a current opponent prove they can mate with knight and bishop in under 50 moves.  Would a GM do that?  GMs know what other GMs know and I'm sure they don't resign when there's a possibility the other guy might miss something.  Youc an see it when they near time control, often the resignation doens't come till after the blitz since they know even a GM can blunder in time trouble, but with an hour on the clock it would be rude. 

I figured the thread would die after the second post offered a simple "yes". But it kept appearing all day as an active thread and I decided to find out what all the fuss was about. My effort was not rewarded. I think people are bored.

Most games end in a draw, but thoes that have a winner and a loser almost always ends in resignation.