Problem is, there’s a lot of really specialized, critical software, that is provided by vendors and throws an absolute fit with any change you could maybe run Windows in a VM, but it may not work with the specialized hardware and networking gear being used, and now you’re spending a bunch of extra time and money setting up a vm if windows inside Linux, which means you also have to train everyone on how to use the VM, adds another management/security issue, and adds another point of failure.

If they ever switch (the entire govt should, it would be so awesome to see the govt resources put into Linux development instead of M$ pockets) it’d have to be a very gradual process, and windows would still be around decades from now for legacy systems. (If the US hasn’t imploded in civil war or the planet melted by then 🫠)