Microsoft does need siloed leadership, they need overall leadership. They have very good and sometime great technologies in various areas. The biggest problem is that there is nobody looking at the big picture.
KIN is a good example of a targeted product but it certainly not what Microsoft needs. They would have been better off having the KIN experience be an application that can load on WM7. Even better, use it as the target for having applications on WM7 work together. Build the framework to support the KIN experience and then let 3rd parties develop the next big thing.
Zune is another example. It should have been an application on Windows Mobile but they blew that too. If they couldn't get the user experience they wanted on WM, that should have been the first clue they needed to fix WM. They wasted a ton of time and loads of money building yet another silo instead of improving their core products.
Microsoft has the technologies to beat Apple and Google but they lack the will and the leadership to do so.