What's wrong with the kernel (and other software) being compatible? Should a company or school not be allowed to force that students use their vetted Linux distro/version combo rather than some custom distro? I would like to ensure my servers are using the right versions of things. I'd use my own key, but if we said "Linux shouldn't even support SecureBoot" then this isn't possible. Having a distro get a key from Microsoft or using its own key are separate things.