A good reason is that people want to use it.
Pardon me if this seems like a Slippery Slope fallacy, but there's gonna be an issue no matter what is done.
If I include a pony tail, there's gonna be all sorts of fan-wank. If I don't, there'll be even more fan-wank, when people whine about how there's no pony tail. And, just the other day, there was this furry on a server who was whining about being bullied, even though he made it extremely evident he was a furry to the people who were bullying him.
Unless I see overwhelming support for this mod, it's not something I'll be considering.