Why do people think government should fund embryonic stem cell research?
The answer: Because no one else is.
The real answer: If it actually worked, private companies would invest in it.
It would be literally flushing money down a drain. The government would be better off taking your tax dollars and going to Las Vegas, picking the game with the worst odds and letting it ride. Because at least then, there is a chance of some return.
Not neccesarily. If the returns are too far into the future, almost no company would invest in it.