Literally all 5 of those are problems with internet users. The gaming community is very much situated on the internet. stuffty internet users who happen to be gamers (as well as gaming's primary demographic of teen to young adult males) are the ones in the Youtube comments, which is probably where this guy got most of his exposure to this behavior.
The gaming community is primarily on the internet now.
stuffty internet users are very much gamers too and are part of the community.
Grown men get into arguments about video games.
People actually get high and mighty about being hardcore gamers.