Oh boy, this sounds like a magnet for religious warfare, but honestly - that is not what I intend from this question.
Today, in a sales presentation, I got my butt kicked because I was trying to sell some software that our company wrote, and one of the audience members said, "Oh the govt should never buy anything from a small company, since you could just go under and we would be left with no coverage! We should only use open source software." Never mind the fact that no such open source alternative exists (there are larger companies, that make similar, perhaps better, but more expensive software). I also offered that as a protection to govt, we offer code escrow. In either case, my answer didn't really go that far.
So my question to all of you (and apologies in advance since this isn't really a programming question, but I don't know of any other SE site that would be a better fit either) is - how would you answer it, if at all.
In retrospect, perhaps I should have focused on the open standards that our software does conform to, but I did not think at that time.