I would argue that being punished unfairly by the server is a much greater “suffering” than encountering a staller.
There is something about “unfairness” that humans simply can’t accept.
“My opponent is this game was a dick” is easily accepted, but “I would have won this game if the server hadn’t arbitrarily decided I should lose” is not.
Not to mention, there are thousands of users, but only one server. If I encounter one opponent with a bad behaviour, that’s not going to affect my pleasure when playing with other opponents. But if I encounter an unpleasant behaviour of the server, I’m going to worry about this server behaviour in all the games that I play on the server.