I don't think it's vigilante culture. People value order and organisation and this coupled with the direct nature of communication, feel completely within their right (I would say feel duty bound) to say "hey, you're not supposed to do that".
It is also custom here to voice one's opinion in extreme precision or detail. "Hinterfragen" question things, criticise, always down to the details. Not in an emotional way but very in a very matter-of-fact sense.
So think of it from the perspective of "if the rule is that you don't cross on red, then why are you crossing on red? It's against the rule". It's not personal at all.