You are exactly right.
These huge military projects (which for the most part are utterly unnecessary) are nothing more than jobs programs cloaked as national security. There is certainly a huge element of rent extraction by defense contractor executives, as well as small business owners who utilize specialized direct award "set asides" designed for minorities, women, service disabled veterans (the vast majority of these are people who were never in combat, and have minor injuries at best such as back-pain), etc. Of course, the large defense contractors simply sub-contract to these small businesses and then do all the work, while the 3 people who constitute the small business pocket money for doing nothing other than existing.
But beyond the rent-extraction, you have a nation with a hugely oversized, overstaffed military. We take people, the vast majority of whom have an average high school record and zero college experience, and then put them into an immensely bloated, 1950's era organization. A small percentage of them will learn how to perform combat operations. The majority of them will learn to perform the logistics functions (supply, maintenance, repair, administration) that are the backbone of any military.
While some of these skills learned (electronics, software, etc) are in demand in the private sector, the vast, vast majority are not. In fact, a huge percentage of the administrative functions in the military have long been automated in the private sector. It is a truly overstaffed, bloated beyond belief organization.
So where do you go when you get out of active duty? If you are like many folks, you are truly fed up with being in a large government institution, and you want nothing more to do with the military. You go to school, aggressively learn some trade/skill that is in demand in the private sector, and you leave it.
The majority of people I've encountered don't do this. Instead, they take the only jobs they are qualified for: "quals" (somebody with military experience in some obscure area of logistics for an organization that is required on paper for a contractor to have employed upon award of a contract) for a defense contractor, or a civil service civilian job in the Department of Defense or other segments of the Federal gov't.
Both are, to some degree, do nothing jobs. A "Qual" might provide lots of advice to a defense contractor they are employed by, but typically they are just there because the contract demands that they are. They are mostly figure-heads. The joke in the industry is that many are hired and hang out in darkened offices playing video games, separated from the software developers and managers who were never in the military.
The civil service jobs in the Federal gov't are like working in any large bureaucracy. Mediocrity isn't just tolerated, but is the norm. People come in at 9 and leave at 3. If you care about your job, you work hard and end up carrying the weight of several of your coworkers who do nothing but watch the clock. Promotions are based on paper qualifications and certifications, are decided by people who have never met you, and are frequently awarded to people who dedicated their time to gaming the paper system instead of performing their job function.
What I am saying sounds anecdotal, but organizational experts who have studied failures at places such as the V.A. have all summed these findings up in a scientific way.
In Arlington, VA, there is a neighborhood called Crystal City. In Crystal City, there is a large, brand-new environmentally sustainable building which houses a huge number of EPA employees. The EPA has a valuable, important mission. For someone like me, it is beyond depressing seeing the employees milling about on 2 hour lunch breaks. The vast majority of them drive to work, despite the building being walking distance from a subway station. There is a mass exodus at 3PM as they all leave for suburbia.
Just like the rest of the Federal gov't, the EPA and the DOD are nothing more than giant employment programs. The difference is that the EPA gets its budget hammered by one political party that hates it, while the DOD is universally praised and worshipped by people who don't understand that the percentage of members who will ever see combat is in the single digits.