Rand Simberg: "The problem is that ... the government ... has always supplied human spaceflight, and when you propose to do it in any other way ... the same cries arise: “Are you crazy?! Why do you hate space exploration?! Spaceflight is hard! Only NASA knows how to put people into space! Who is going to do it if not NASA? These people are just hobbyists in garages! What if all of the commercial companies fail and go out of business?! ... What if they can’t hit their cost targets? What material will they use? What if we can’t store propellant in orbit?”

I actually have heard people make these arguments. I have a pizza bet with one of them. Read the whole thing.