If you want the pure Metro version then just buy an ARM tablet. The battery will last longer, and none of that awkward old-fashioned desktop software will run on it, so you won't have to be bothered by it!
If you wanted a tablet that had no compatibility with Windows - why would you get a Windows tablet?<p>You are stuck in the problem of either adding a 'bit' of backwards compatibility until you get into the state of supporting 1980s netware apps because some customer in one focus group mentioned them. Or you deliberately change things to differentiate it.