Sadly, Sebazy, I don't think these kinds of people will stop no matter how many times people show them how their opinions make zero sense...since they haven't done the content they are constantly complaining about or played with the subset of players (raiders) they constantly complain about.
I am starting to think that what really drives certain people is simply jealousy and the reason I came to this conclusion is a lot to do with how some people insist on claiming nonsensical things about the raiding community and the game that they have no experience with, no logical thoughts about, and no facts to back up their opinions with. So they are simply baseless opinions...which makes said opinions pretty useless, and also serve no real purpose except for the one person those opinions belong to.
They are jealous that players are able to do and complete content that they haven't or don't want to put the effort into doing, so then they simply take that jealousy and seek to diminish other player's accomplishments by creating reasons why that accomplishment isn't that good or that there is a negative stigma attached to the subset of players who complete these accomplishments and claiming things like "Well, they all cheated so it's not like they legitimately earned it." even if no factual cheating was even present.
If they can spread these kinds of thoughts it also makes themselves feel better that they don't have said accomplishments since they literally talk themselves into believing that it wasn't actually hard for those players to achieve it (Savage mechanics aren't even hard! They cheated! They got carried! Enrages are the only thing hard about savage! It's all luck, not skill!) and they comfort/assure themselves that if they wanted to they could complete it/get the accomplishment too, despite not actually knowing how hard the content is personally since they have never tried it.
They also use it as an excuse why they won't do that content because of reasons like "Well, I don't want to be like them. I don't cheat!" so they can disassociate from players who actively do that content so they don't have any obligation to prove to themselves or to others that they can complete the content too. If they don't try they can't fail, so they stay in the protective safety of just snubbing the content, and the players who do that content, from the sidelines while constantly railing against it all.