Recently, Ubuntu designed a new desktop environment that is very, very different to the old one. It just happens to use round rectangles around the icons in the dock. It still uses the same indicators, programs, file manager and settings panels. It even has windows and menus like a regular desktop.
People hated the change because of the fact that they had gotten used to the old one, and because of the round rectangles they complained that it was a "tablet interface".
How on earth could Microsoft think they'd be immune to this? Metro is developed directly from Microsoft's smartphone GUI, does not allow multiple simultaneous windows, and doesn't even run the old programs (except for a special legacy compatibility mode). Microsoft should have been able to see from the Ubuntu reaction that most people wouldn't want a drastic different interface.
Microsoft's Metro also seems rather half-baked and lacking in style and functionality.
I wouldn't recommend any software by a company that saw criticism of its competitors and thought "No, our users will be happy even with much bigger changes."