So, why isn't this a thing yet?

[Dererk]

I think a better question would be whether or not the pros outweigh the cons.

Cons: SE is inevitably hurled into a blazing firestorm of controversy for allowing children to be maimed, mauled, and sexualized.

Pros: Some people get to play as a child, for whatever reason.

Seems pretty obvious.

Yes let's not also forget that this is an online game that you play with other people so social interaction is a thing. You take that and let people be able to play as a child that's going to cause problems. You never know who's on the other end of the screen plus we do have a marriage option in the game so how'd that even work.