Those manufacturers were notorious.
The problem isn't really the the manufacturers and it's not just limited to the military. The problem is congress and the way they write appropriations bills. They get very detailed about the specifications for items that they are appropriating money for to the point that no over-the shelf mass produced consumer product could meet the requirements.
For example, way back when they still allowed smoking in federal buildings, Congress appropriated money to buy ash trays for the desks of federal employees. Not only did they have to be glass ash trays, Congress specified that they had to break into X number of pieces when struck with a hammer.
I don't know what X was, but I do know that Congress did supply a specific number.
Those ash trays cost a lot more than any ash tray you could by in a store, and it wasn't because the manufacturers were being greedy.
While there are companies that live or die by the ability to sell to the government, a lot of manufacturers with large civilian customer bases simply aren't willing to put up with all the BS, hoops and red tape you have to go through to sell something to the government.
Yes, the government makes people jump through hoops to sell the government things the government wants. Naturally, the few companies that are willing to go through the process want (and probably deserve) to get paid for all that extra effort.