Wonderful, the kid who got in with the make a wish foundation now has porn up already!
Uuugghhh.
Welcome to the Internet. hope you're sitting comfortably, things can and will only get worse from here.
Yes R34 exists, but I never heard about Dexter infuriated fans making disgusting porn of that one episode that was written by a kid purely because the makers of Dexter's Lab dared to have an actual kid involved with the creation of an episode.
To be fair, most fandoms, Bronies certainly included, are full to the brim of slimy fuckers.
That goes for any fandom. Bronies are just vocal and stupidly proud about it. Why, I have no idea.
By theory is that they're extremely insecure about enjoying a little girls' cartoon, so they freak out in their attempts to make it seem more mature of a cartoon than it actually is.
Granted, Rule 34 of everything exists out there (by definition) but a lot of people trying to prove that they're not manchildren leads to a lot of stupidity.
which I don't actually think applies to this scenario: I think it may have simply been someone doing it for the lulz and the outrage. Though that's the optimistic interpretation.
The other optimistic interpretation is that they didn't realize it was a kid's OC.