Derpy. Because Derpy.
Seriously though, I think it's all due to the fandom. Derpy doesn't get very much attention when it comes to official development. Fine by me though because we're doing a pretty good job of developing the living daylights out of her. I've seen a lot of Derpy art that just makes me daw. I treasure her scene in The Last Roundup too. So, with that in mind, I regret nothing.