That is the real problem of this issue.. the slippery slope and what exactly you should change. The only real reason I can understand having sex change as a common option is the fore mentioned family that just can't seem to have that girl they wanted. Then they could.

What we really need is some sort of fair regulation. Something that allows it but keeps it in hand. but what is kept in hand?

I think many don't like this cause it raises issues that aren't black and white. It ain't easy to pick out. As long as people keep individuality(apperance and mental) then I am mostly fine with it. The question is ... when does it go overboard?