Okay, extrapolate this to a weapons system. You can't expect a company to come up with their own version of the F-35 (which is extremely advanced) with the hope

Okay, extrapolate this to a weapons system. You can't expect a company to come up with their own version of the F-35 (which is extremely advanced) with the hope that, if you are satisfied, you'll buy 100 or so. If the government will not go at risk for this, there is no way a company, with vastly fewer resources, is going to do it. I've bid weapons systems and built weapons systems. I can honestly say that you make your very best effort to come up with a realistic proposal (we aren't trying to rip off the government. I'm just as much a taxpayer as you are). But there are limits. Detailed requirements are only going to be known well after you start. The government doesn't know how to specify the requirements - in large part that is your job. When you bid you want to be sure that you can be profitable, but then you also have competition, and a blind process (you don't know what your competitor is proposing, and at what price). This limits collusion, but the lack of information makes it hard to write a good proposal. Company A might think feature X is important, and put that in the contract. You didn't. Who is right? You'll find out when the contract is awarded. Opps if you got it wrong. Once you win the real "fun" begins. If you are lucky the program office running your contract understands the nature of research and the unknowability of the future, and works with you to set a reasonable scope for the project, and works with you as more information is found. OTOH you can have a bean counter trying to protect their career by counting "shalls" in the document (a legally binding term) and ensuring that each one can be checked off with what you deliver. Doesn't matter if it is rational or not. And then there are copious documentation requirements. The intent is that these requirements be tailored to the contract and needs, but again bean counters can intervene and have you doing massive amounts of busy work. A great program officer will stream line it and have you doing effective work. But, you know, there is not infinite money to prototype, build, test, scrap, and build again. You have 1 billion moving parts (figuratively) that you are trying to track and optimize for, and you kind of work your way to a solution. that is, unless you can afford the project to cost 10x as much (you are already complaining about cost, so that is a nonstarter), or take 5x as long (why don't I have my jet yet?!?!). The result is, unsurprisingly, unoptimal. tl;dr: weapons systems are an extremely expensive mix of state of the art research/development/deployment all in one. It is not going to go smoothly. It is the worst possible way to do a project, except for all the other ways, which are worse.