I'm sure there's a barely functioning business critical app that runs exclusively on Windows NT in their administration that would beg to differ
But certainly we are already at stage where Windows NT can be regenerated on the fly from a prompt anyway, aren’t we?
Otherwise, there is also ReactOS that could be leveraged on for that kind of scenario. I wonder where it would stand by now if all the money that governments around the world spent in Microsoft license would have been invested in it instead.