So, why isn't this a thing yet?

[Chambers]

what if SE handles it responsibly

The issue isn't how SE handles it, it's the players. SE could just have easily made the Au Ra children, but they didn't, because they know just as well as we know, that we're not responsible enough to use the characters as intended. It's crazy to think that they'd spend the time and resources to go through censoring all the armors, possibly have to change the ESRB of the game, and fight off media flak to add children as playable characters that will, in the end, cause more harm than good.

Just be happy with what you got, and hope that if we get another race it's a little more creative than humans with <insert animal bits of your choice> tacked on. Realistically though, the next thing we get would probably be Viera.

Basically, at this point, you're denying everyone the ability to do something based on the actions of a few..

And a lot of people have voiced against the idea, and forcing them to have to play in a world they're not comfortable with because the opinions of a few is just as bad.