No, it is a compromise to facilitate universal app development. Of course they could punt on it and then people can just keep whining about not having the same version of Office as ios and Android, or should the maintain a separate development track just for a few people here?
No Stephen. Either way, there is zero need for a second development branch. The touch Office apps already contain a lot of code that is executed conditionally, depending on what type of device the app is running on. Ideally, app developers would have to do very little of this UI reconfiguration themselves, provided MS has thought out a default mapping between the large screen and small screen layouts. The ribbon at the top being moved into the bottom command bar is one example of such a reconfiguration, that likely occurs fully automatically for app developers.
These questions raise zero technical problems that aren't easily overcome. The only difficult questions are these:
A) Is it most important for a UI to be perfectly tailored/optimized for the screen real estate that is available, or is it worth sacrificing some of that optimization in favor of having apps be visually more similar across large and small displays? It's impossible to have both.
B) What is the benefit of spreading navigational chrome and command buttons across the screen (in top and bottom app bars and side panels), vs finding an approach that keeps them more out of the way and in one spot at the bottom, and also keeps mid- to small sized devices usable with one hand?
C) Is there no way to evolve the Metro design language into a more capable version of itself? A way that provides more utility while staying true to its principles, or is it necessary to sacrifice Metro in favour of other benefits?
There are probably more, but those are the most important I think. People can have valid reasons for answering those questions differently.