No the reason is that there are fundamental differences in the risk profile of the civilian and military sector.
Adversaries will insert spies in mission critical projects if they are publicly accessible. Once the main contributors stop maintaining the project the military will have to hire people and train them for maintenance but all the people that can train the replacements have already left. The military has to verify every single line of code every time the code base is updated.
All of these problems don't exist in projects where the full life cycle is taken care of by the military.
The internet of things suffers from the same problems. Once you are dependent on a vendor and that vendor shuts down or cancels a product you're stuck with a lot of paperweights. The vendor is usually not acting in your interest.
