The "comment police" bit is an interesting observation - much of the really petty hostility seems to come from mid-tier power users instead of mods and high-level contributors. I think the article here undervalues how unpleasant it is for a new programmer to get even a single response of "Seriously? Marking for deletion."

Those comments might get removed later, but saying "trolls are everywhere" is too pat when the people abusing new users are very visibly established, popular members of the community. Getting attacked by a random throwaway account is a very different feeling than getting attacked by someone up near the top of the totem pole.