Yep, online blitz is a cesspool of rude behavior. I try to take a zen-like approach to it myself but even I sometimes fall into the cursing and ranting... :-(
I played one game where my opponent's first 8 moves were pawn moves. I won the game but was very annoyed that he played so silly and "wasted' my time even in a G5+5. I think I called him an idiot after the game and then I felt petty and logged out--fortunately this is about the worst behavior I think I've fallen into.
Blitz and the anonymity of the internet combined definitely cause decent people to start to not act so decent. That's when it is time to log off chess.com and go and analyze some of those losses you just endured.
... for you and the game you two just played.
I am not talking about OTB. And i am not talking about friends. Things online are completely different. Even thou you won quite nicely and overhelmening, he would say he had advantage and that he should crushed you and he was the better player and you did not desirved to win. Sounds familar? Ofcourse. 90% of chess players are like that in online blitz. I myself numerious times cursed and insulted my opponents and they did same to me. Things can go even further with rude private messages, words about your familly ,you know... Just look at every single members (not those with membership, they can delete notes) wall. I mean really every single ones. I have checked about 30 at least complely random members and all have "nice" words on the wall left by other players.. All that is wrong and should not be.. And why is that...
Well interned provides you with the priveleges to be anonymous, hiden, nobody sees you, nobody can reach you.. nobody can do things to you as if you were OTB face to face... It's very easy to be rude.. to be someone that you can't be in real life - everyone want to trash talk, "smash" his opponent. Nobody want to be friendly (after a loss) insted they insult you.. run.. block you etc.
Nobody says hi or good luck or oh that was a good move like old days back 10 years ago.. Not even a simple GG when the game was really good for both players.. All run.