Why do they do it?

Man....I really hate it when my opponent abandone the game. So do you wait 40 min. for the win, or just forego the game and move on (which is what your opponent wants you to do). One would think after no play for 42 minutes,  the website would recognize abandonment and end the game. But no. So here i sit.

Fear of this happening in longer time controls is why I only play 10|0.

Mmmm...

Just my opinion, but why stay in it? If you improve your game significantly your rating will increase. One game isn't going to override that.

Simply by playing longer time controls you are already agreeing to a game that can last up to whatever the sum is of both players' starting clock times

I lost a game recently to abandonment but I didn't abandon the game, It abandoned me. Something happened with my internet and I lost contact with the site and my opponent's clock was running on my system but my opponent had moved and I had no idea it was my move. By the time I realized what was going on I had used up all my time. I think I refreshed the page in disbelief that my opponent wasn't moving , and lo and behold I was right. By that time it was too late.

Don't always assume someone is doing it to be a jerk. It so happens I had this happen in a losing position so I'm sure that's what it looked like. It was only about a minute and a half in my case though. But it was certainly not intentional.

It is an impolite thing to do, but if the rules take that into account then you have to accept the fact that it could happen.

Especially if you play over the internet you have no way of knowing whether the player is legitimately taking a long time to think what their next move should be, whether they have fallen asleep (this has happened in live otb chess. A player could be playing late at night and fall asleep.), or whether they actually intentionally abandoned a game.

It also has to do with another invalid complaint some people voice here in the forum. Some people get annoyed when their opponent keeps playing even though the board looks like they should lose. I think the players who keep playing are doing a very correct thing. It is a legitimate tactic especially in short blitz and quick games. The frustrated player who arrogantly think they won will get further impatient and frustrated. They become increasingly likely to make a blunder in response to the opponent who refuses to quit. They could also lose on time despite being up in material and having superior position.

So, I recommend to anyone who is a new player who just began playing online that you never resign even if you think you will lose. Try to get a draw, a stalemate, or even take a chance to win on time. All of these are legitimate tactics which the rules allow.