"but sit down with someone in real life and you'll find it is rare to only play a single game with them"
It commonly happens where I only play one game with someone and then the next challenger arrives. If there is no "next challenger" then we will play another but this is a special occurrence.
OK but that is in real life where you can trash talk your opponent for fun and he'll do it right back knowing its all in good fun.
where internet chess seems to attract many with bruised egos, and many insecurities
There must be something special about New England then. I've played chess with people all over the world, in many public places, and with opponents who don't speak the tiniest bit of English, and have found that it is rare for a rematch not to happen. The few times I can recall were because we had a single board and a long list of challengers.
Maybe online it is not as common, but sit down with someone in real life and you'll find it is rare to only play a single game with them. Also I didn't say people were entitled, I just implied it is the more courteous and respectful thing to do. And again, you can always disable chat just long enough to tell them you need to leave. Me personally, I like to be friendly with the people I play with and greet them when we start playing. If someone has chat disabled I tend not to even care about the game, because I might as well be playing a bot at that point.