I doubt anyone here is against a high level of competition regarding govt purchasing. I know that I'm all for it.
But when I read complaints like yours ...
The NSA found merit in Linux, and was working on a hardened linux project to develop a highly secure strain. Microsoft lobbying put a stop to that.
I realize that open source proponents aren't happy enough with a seat at the sales table. They want govt money (our tax dollars) to be spent developing linux. The SE-Linux project that you referred to is the perfect example.
The mainstream doesn't lobby for government contribution to Linux. They do lobby for a fair shot on an even playing field against closed source software. The NSA example was the preeminent security agency toying around with Linux to see what they could do to harden it, both as a theoretical and practical exercise. Wouldn't the NSA have an interest in using a good base to create a highly secure operating system for it to use? Microsoft didn't like the implications of a Linux even farther surpassing Windows that it currently does, so had it stopped. BTW, the NSA had no legal obligation to return any added source code to the general Linux population.