Building locked-down systems is not Microsoft's core competency. A big factor behind Windows' success was the massive developer support they received. With a few exceptions (like the undocumented ATL libraries), developers could do whatever the hell they want. They got a vibrant ecosystem in return. It looks like the same strategy is working for Android even today.
> Now, we're basically getting iPads, but with bright cyan colors and a chronic inability to fit huge 128pt words on one page. "MUSI" "PICTUR" "SOCIA"
Looks like you're totally ignorant of the Metro UI design philosophy. Have you actually tried a Metro device or are you looking at screenshots?