Ponies And Fun, Or Not Too Much
I am more than okay with people not liking the show if they have legitimate reasons for not enjoying it, because opinions are the basis of discussion and communication is good!
However, disliking the show and it's fans because of some outdated belief that the world is blue and pink and boys should not enjoy things aimed at girls really rubs me the wrong way. As does, in fact, the very thought of disliking someone because of what they like.
And being perfectly honest, letting other people's actions/displays of fandomship bother you is really silly. You should allow other people to have what they wish in their av/sigs just as anyone else, and if it really bothers you that much, just use an adblock.
tl:dr: this is silly. If you don't like it ignore it and if you do, great. It's just a fad. I'm sure it will pass soon enough.