At the highest level, Metro design feels like a case of design overgeneralization. It tries at once to apply the same look & feel principles in Touch, Desktop, and Web context.
Reduced discoverability is the exact issue XBOX Live's interface has had since they updated it -- it's harder to differentiate between content I've paid for, their internal marketing and external advertisements to the point where I deliberately avoid them and just use the XBOX button modal to navigate. There's no rhyme or reason for the element sizing, outside of [apparently] making all of the stuff that's actually relevant to me the smallest.
At the highest level, Metro design feels like a case of design overgeneralization. It tries at once to apply the same look & feel principles in Touch, Desktop, and Web context.
Jack of Many Trades, Master of None.