Question: Does anyone think if MS simply kept refining the Windows 7 desktop in Windows 8, and added Metro as a first-class option but not forced on us, that Windows would have sold better or worse?
Exactly this. It's almost like some marketing/MBA-type higher up decided to cram this new UI down everyone's throats in order to leverage Windows desktop dominance into the phone and tablet realm. Maybe he/she was surrounded by people who were afraid to say this was a bad idea. This kind of culture does not produce good software... Did they even look at OSX? Their app store is a desktop application because it's a desktop OS. The desktop shouldn't be an "app" on a desktop OS.