"I agree that we won't stay on this planet for the next 100 years no matter what Nasa does, but to me the question is whether the US government should continue throwing money at manned spaceflight."

Oppose to throwing money at unmanned flight? NASA wouldn't get any funding if it didn't have a manned spaceflight.

"I thought that most of the regulatory hurdles for private spaceflight in the US had been removed."

Some have been, but it's an ongoing battle with perhaps odds favoring the guys who love to order us around.

"Aside from reasonable protections for innocent people on the ground, government should stay out of the way of private manned space efforts."

The key problem is that spaceflight has an international aspect, and in terms of international law, govt is the responsible party. Because of this socialism view that people are peons, we are at the whim of your govt.