It's a bad operating system, no doubt about it...
I just had this discussion last night. It's built to be particularly friendly with tablets and other touch interfaces, but maintained the desktop interface as an alternative to appeal to traditional Windows users. As long as the desktop exists, people writing software are still going to write for the interface. It's easier, and the mechanisms to launch and operate your software out of the desktop interface already exist. Hell, Microsoft is still writing its own software for the desktop interface - Office isn't even fully compatible with the touch interface. As long as they leave that easier, use-the-desktop out, the touch interface is never going to work as they wanted it to, and the OS is always going to be unnecessarily bulky and less user-friendly than Windows 7.
On the other hand, in most performance metrics it is at least a little bit faster...