I agree with you 100%. It seems as though the UI team came up with this concept, which is a cool prototype, but naively misses a lot of the functionality that the standard interface has evolved over time. As such, it either needs to be better integrated (e.g. just an active desktop + widgets all over again with some flashier task switching) or purely for mobile devices (say a special edition you can install). As it stands it's an ugly hybrid of both UIs that just screams "we don't know how to make this work well for regular daily operations (e.g. file management)".