Not sure what the alternative to private business building this stuff would be, since every weapons system we've deployed since the 18th century has been built by private enterprise.
The Deepwater project was a cock up because the Coast Guard lacked the personnel, expertise and time to review, understand, and approve any design tweaks from what they initially approved. This made it possible for bad design, corruption, etc. to screw the program up.
A good book I just finished on how private enterprise made winning WW2 possible is "Freedom's Forge". Once the government got out of the way, companies like GM, Ford, etc. started pumping out so much war material that Japan and Germany were doomed. I believe the record Kaiser set for getting a liberty ship from drawing board to water was just over 4 days. NYC is still trying to finish the 911 memorial.