Former US CC Champion Edward Duliba refused to play chess on the internet because he felt you meet the most rude and crude players of the chess world there.
Human beings tend to be competitive and sometimes chessplayers even more so. After all, chess is a competition and, like other forms of competition, showboating, a condescending attitude, trash-talking and bullying are not unusual. Rude unsportsmanlike conduct isn’t unusual. This seems especially true on sites where players are anonymous and they are free to act like people who write on toilet walls.
J.C. Hallman in his book The Chess Artist explored the world of chess as an outsider and a non-chessplayer. He concluded a lot of us have obsessions, quirks and display antisocial behavior.
Good sportsmanship is about playing by the rules, discipline, respect, and self control. A good sport has fun because he enjoys playing the game more than the final outcome.
Buttheads display the following behavior:
1-They are all around poor sports. They like to insult people.
2-They make abusive remarks or use foul language.
3-They like to spout their religious or political views.
4-They like to tell you "Good game" but only after you fell into a one mover or hung your Queen and resigned. Genuine compliments are unknown to them. When they win they like to gloat and rub it in.
6-When they are losing they never resign. They would rather disconnect or run the clock down. In correspondence play they take as long as possibe to move.
7-They never show any respect for their opponent.
8-They do not respect the rules.
9-They do not play fair.