Here is what happens...

...when the killing of living members of the human species for spare parts becomes socially accepted.

And once again, it's worth remembering that fetal stem cells have yet to lead to a cure for a single disease; that it is by no means certain that they ever will- and that if they do, it will probably not be for decades, during which time more promising and less ethically dubious alternatives which are already yielding cures will have had a chance to develop even more than they already have.