Metro is about MS making a homogenous look and feel across all possible platforms,
I agree with this.
and thus, having to go to the least common denominator (cell phone interfaces) for all of them.
I do not agree with this. I think that cellphones are, now, the "most common" denominator, not the "least" one. There are so many smartphones around, that now people are more used to this kind of interface, so it does make computers more usable if they agree with the paradigm. I also think this is shit for "power users" or "developers", but that is less than 1% of the market, so MS will not care.
You're already carrying the sphere!