Being a brony is part of Euphoriac stereotype. It's not taking a jab at bronies in general, it is taking a jab at Euphoriacs with bronies, highlighting the fact that liking My Little Pony and having a Euphoric attitude seem to clash a bit. After all, if you're constantly squawking about how stupid theists are and how enlightened you are compared to them, you're not going to develop very many Friendships, with theists or with atheists.

And then of course there's the issue that FiM has a lot of mythological themes to it. It's more about the hypocrisy of the Euphoric philosophy than anything else.

Some would consider that picking the low hanging fruit.