It has been most of the US history

i think this an example where government intervention came about the right time (but it was unintended as it came as the result of the war).

once electronics got complex the whole development process got more complex and required much more r&d - that added to the costs by an order of magnitude. That was beyond what most private companies could afford at the time - given they were just past the great depression.

Also people probably weren't used to view things as a system, that was a quite different paradigm. I think I read somewhere that thinking in terms of systems was one of the big changes that were the result of the war.