First, there seems to be a lot of agreement that the Metro interface is innovative. I think it's also a meaningful innovation, but each to his/her own.
Second, pretty much everyone would agree that the early Android versions were not really innovative and pretty much a copy of iOS (which is certainly not the case anymore). Also, history is littered with inferior systems with little innovation that eventually won. So, it doesn't seem to be the case that the consumer necessarily chooses for 'meaningful innovations'. There's also price, branding, luck, etc.
Third, it is very strange to compare RIM and Windows Phone. RIM is more like Apple: one operating system, one device vendor. Windows Phone is more like, erm... Windows ;) or perhaps even Android: one operating system, competing device vendors. The dynamics are completely different, e.g. a phone vendor might choose to push WP or Android more, depending on what is offered in terms of differentiation, royalties, patent licensing costs, etc. Also, like the grandparent says, Microsoft as quite a popular ecosystem to leverage WP (Windows, XBox 360, Office, etc.).