You're using that meme wrong.
Barneyfag is what a faggoted 4chan troll called /mlp/ users instead of ponyfag. He thought because MLP is on after Barney, they're both just as shit. They are now, but they weren't then.
Then Barneyfag became what people called that faggot. The face and name of the "If something is for kids it's shit and only shit adults like it" idea.