I think the controversy behind MLP and the reasons why "bronies" are so defensive, goes to a deeper psychological root. MLP has a lot of feminine base/estrogen in the show, and therefore bronies get so defensive because they don't want to be seen as "less than a man" and therefore weak, or inferior..
Although some would never directly state it, all such ideas are based off of stereotypes. Who you are has nothing to do with how you express yourself. With 7 billion people on this planet, I doubt any of us are going to fit into one box or another... Include that with everyone possessing an animus/anima or masculine and feminine traits within them, regardless of biological sex.