Take the requirements for example. If they aren’t airtight, you’ll get into a wordsmithing scenario where the contractor claims they met the requirement and it becomes a game where the team with the best lawyer wins. Write the requirements too explicitly and contractors will push back saying “tell us what you want, not how we’re supposed to do it.”
A somewhat silly example is if you specify you want unit testing on all safety critical code paths a contractor may claim they define running a compiler as “unit testing”. A contracting officer may not be technically savvy enough to push back and when the subject matter experts try to leave negative contract comments (that get reviewed when awarding future contracts) they get scrubbed because its not worth the fight in the eyes of the contracting officer.
Unfortunately, just saying “do good work” just doesn’t...work
With DoD you have to add in various accountability steps, political footballs, public opinion, etc.
If you've spent time around the DC area you'd be shocked at the number of adverts for things like the F-22 that you see. One time I took the metro from NoVA to MD, with a stop off downtown, and counted at least 6. They're not just bringing lawyers and playing contractor games, they're aggressively marketing to everyone.
Those kinds of purchases being swayed by subway ads... I really hope it's a joke.
The F-20 may have been the last time an aircraft company ever pitched an airplane developed on the company's money. Despite being highly praised by all who flew it (including Chuck Yeager), it's ugly demise at the hands of politics (it was less than half the price of the F-16) was an example to all to never do this again...
The problem with massive development efforts like this is that there aren't a lot of competitors. In this particular field, there are two, and not really even quite two exactly.