The Linux desktop experience is a bit like watching an alcoholic. You try to explain that drinking is making them sick and they should stop, but they just get violent and drink even more.
I think the success of Windows should be proof enough that you can keep compatibility for very old APIs and that it's required for an OS that is to be a platform for other people to build software on, as opposed to a walled garden (Apple) where you sometimes let people build part of it.