What's so surprising? OpenBSD folks don't fall for the next new shiny thing. 10 years from now, something else might take over git, and everyone will jump to it. OpenBSD folks don't care, if what they have works, they stick to it.
Whether that's because there's a demand to host the code on Github as well, or because they like Git, or a little of both is something I wouldn't presume to know.
Using CVS over git in this day and age is a very dumb decision. They may make up for it in other, good decisions. But this decision is a dumb one.
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.
(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.
Probably migration to svn would be smarted since it doesn't change current workflow, granted they actually have a need to migrate.
What is it with this obsession with telling people how to get sh't done? If they write their code on used kleenex using wax crayons and share that using carrier pigeons, I don't give a sh't as long as the finished product is fine.
Most readers have no way of evaluating their crypto primitives, or their nuclear power plant, or a zillion other things.
But we can evaluate their source control!
The main reason is that CVS works well enough for our purposes. Most of the diff sharing and discussion happens over email anyway. That's where all the action is.
The main use case is that CVS distributes OK'd patches and allows us to revert them if they are later found to cause problems.
Everyone works on the head branch so there are never any surprises caused by delayed integration. Instead of using branches, the workflow switches between development mode and release mode when the time is right. Release branches receive only a handful of patches (usually less than 10) for the most critical issues discovered during their 1 year maintenance period. Again, CVS is entirely adequate for that.
It's not like there was no usage of git at all. Some devs actually use git in private and even mail git-generated diffs around. If those diffs fail to apply to the CVS tree the burden is on them to fix that. Since x.org runs git, all the X11 and other graphics code is ported to OpenBSD in git branches by our X maintainers and committed to the main CVS tree once it's ready to go live. This can be cumbersome but there's always a price to pay when integrating code from third parties that use different tooling.
You don't provide any compelling evidence to the contrary.