[nickik]

Well, NASA had the right initial idea with the Shuttle, it just that their execution and then evolution of the idea was a total disaster.

[ethbro]

To frame in a comment we often hear around here: if you don't control your funding, you don't control your destiny.

Building anything for the US government that's big enough and has potential military applications is virtually inviting them (and the large project procurement morass they bring) to become involved.