They pick on people who makes bad content on the net and call them out for it, thats it basically. If other regular users sends death threats thats their own fault
But it honestly is. There are very much wrong with it.
1: I won't even call what they do jokes. They use stuff like "Shit" "Ass" "Penis" Fart". If its target audience is little kids they might score on quality jokes, but thats about it.
2: Like i could put a commentary by Nostalgia Critic over any movie and it would basically have the same effect. And the game commentary when complaining about something being so hard and cursing and stuff its done for comedic effects and not to be informative. Although some people have called them out for it but they reply with "Well duh, its just for jokes". So i say, well if i make up my own angry character go around and calling every youtuber horrible, is it ok if i say "Well duh its just for jokes". I mean it works the same way. The thing is the game is not so hard as they ham them up to be, as i have tried some myself.
So the humor and content in generally is objectively bad. Its just that the target audience existed since 2007 and it hasn't moved much since then, atleast some.