people who actually gets turned on by ponies/furrystuff/anime are all in the same deluded boat as far as i'm concerned
'Eeh... I'd argue that, but you're right on it being a special interest based off of fictional creations which aren't very representative of people. (Anime depends on the art and all really, but I'll give you this point.)
You like what you like though. I certainly never made an active choice for my tastes. Puberty strikes and suddenly I like all sorts of things I'd never expect to.