And why is that?
Why hasn't there been Windows on a Tablet? Bloat, plain and simple. I used to work at HP where they were TRYING to use Windows CE to power various devices. Every time it failed miserably and they went back to using Linux. No change in hardware, but change in the OS made all the difference. Why? Windows CE was a piece of junk for two reasons: size and shoddy programming. The engineers had to manually write patches for the buggy Windows code base so basic drivers would work. And the CE install size was 10x the size for the same functionality in Linux.
It's not the hardware, it's the OS. And saying that you have to have a dual-core proc with tons of RAM to run an OS isn't really a big pat on the back to me regardless of the platform.