This is a locution which might be interpreted in more than one way.
What I am getting from your further remarks is that you mean that any thread here that discusses matters of substance will always have some responses that contain (what you call) hostility and invalidation, done by “the standard kind of troublemakers that inhabit the Dope”. These words, especially “hostility and invalidation” and “troublemakers” are judgments on your part. Other people of good will may not share your interpretation of those posters’ behavior. Disagreeing with you and arguing against you is not hostility towards you. If the arguments are properly aimed at the subject matter and not the poster, that is not aggressiveness. If the arguments are directed towards the poster, that is not allowed and it is the job of the moderators to step in and stop it (and the job of other posters to report it).
This last sentence I absolutely disagree with. There are lots of heated arguments here that are conducted in good faith, and plenty of good posters who participate in them. Are they all “aggressive and hostile?”
If you don’t wish to have people argue with you, that’s your prerogative. I don’t think you should make your dislike of argumentation into a moral high ground, from which you snipe at the rest of us.