Before now, because the Department of Transportation was too busy guarding NASA's monopoly on space transportation. That's been broken now (thank you X-Prize!). If you can't get to space, it's hard to develop it.
I, for one, think the government has turned the corner on this (twenty years too late, but let's take what we can get), and is ready to get the hell out of the way of private enterprise. The next five years will tell us for sure.
Fact is, there is so much investment money sloshing around that nobody knows what to do with it so they bid up houses and cars to 10 times their real value.
None of that investment is going to space development any more than it is going to coalfield development in Alaska. Why not?