It's not pretense, it's etiquette. Used to be kind of a big deal, when imageboards were much, much slower. Consider that a thoughtless, pointless thread will remain for months, rather than be bumped off the board in a matter of hours. Yeah, people used to treat "self moderation" seriously, before imageboards became too fast for moderation, let alone self moderation.
Although, I'm more of a fan of the idea of filling a pointless thread with interesting discussions, rather than simply expressing discontent. Let him that would move the world first move himself and all that.