Sorry, but have you ever considered that bronies aren't trying to push their obsession into your face, but you're just overreacting whenever you accidentally running into it? How can you even tell if they're trying to shove it down your throat? They're using things like DeviantArt and the Steam Workshop exactly as they're intended to be used for, even though they could just be unaware of how much they're doing it.
I think the main problem is, is just how active the fandom is. It's so active, that there's just a lot of fan-made work. So much, in fact, that you're going to find it in lots of places you go. You'll just have to get used to it until the brony phenomenon dies down someday, even if it pisses you off at a great extent.
Just throwing in my 2 cents before making a dash toward the door.