They aren't using CVS over Git. They're keeping CVS instead of spending months on a migration path to move to a new system that, while has some benefits over their current solution, does essentially the same thing as their current solution, manage source code. They then take all the time they saved not migrating to Git to patch bugs and continue their release cycle so that the next time a critical SSL or SSH vulnerability comes out with a fancy logo and catchy name people don't deride them on Hacker News for wasting all that time moving to Git instead of working on their security products.
But, if you don't think you can contribute code or money to the BSD folks, but really think that they are stupid, you can certainly convince them that moving to git is a good idea by developing a roadmap and reconfiguring their infrastructure. I'm sure they'd appreciate your effort.
You're assuming that any productivity gains made by switching to git (or something else modern) would be overshadowed by the time and effort it'd take to migrate. I don't have any evidence either way, and I bet you don't either.
(Most) people don't use git (or hg, or whatever) because it's shiny and new, but because it gives them a better workflow and higher productivity.
As I said, I'm not assuming anything, and don't know either way. I suspect you don't either, so it's silly to reject the idea of migrating out of hand.
Why do you suspect that? I was an openbsd developer. I am quite familiar with their workflow, and cvs suits it perfectly well. There is virtually no gain for them to move to git, and a ton of pain.
But, if you don't think you can contribute code or money to the BSD folks, but really think that they are stupid, you can certainly convince them that moving to git is a good idea by developing a roadmap and reconfiguring their infrastructure. I'm sure they'd appreciate your effort.