You seem to be forgetting (or just never noticed) the
thread Thar made about shaving. The title made a silly remark about him being one step closer to being a man and then the magical stufflord Menen comes out of nowhere with this gem:
As long as you are a Brony you can never be a man
There was no discussion about bronies in that thread until he showed up, and the only MLP related material was Thar's avatar. Hell, I probably wouldn't even know Thar had any interest in the show if it wasn't for his avatar, I never even see him talk about it. What Menen did was completely unprovoked and childish, and pretty much the epitome of what the OP is about.
You seem to be the person who thinks nobody can have an opinion :-------D
Building on the discussion of opinions, there is some odd phenomenon that goes on with MLP in how simply mentioning it acts as a beacon to all the "haters". I could understand if it's a particularly annoying user or if it was getting out of hand, but more often than not merely posting a reaction image or quote would piss off some people who would then rush to share their opinions about how awful the show and the people who watch it are. I have never seen this happen with any other franchise.