I initially thought it was because of the Exynos processors in the Note 10.1 but I don't think Microsoft has approved a Smart Glass app for any Android 10" tablets. It does work on the Nexus 7. Microsoft could be trying to push The Surface or perhaps they're trying to figure out the layout for a Android 10 inch tablet, but they do oddly have an iPad version.
IGN had this to say last October "SmartGlass is available now on Android phones and Windows 8. Microsoft plans to release it "soon" for Windows Phone 7.5, as well as iPhone and iPad. Unfortunately, it looks like Android won't get a tablet-native version of SmartGlass any time soon."