After a six-month experiment with Android on a Nexus 5, I couldn't disagree more. Separating the folks who make the OS from the folks who make the device just leads to compromises.
Apple has the right model. Just look at what they've managed to do, for example, with battery life. Nobody can match the hours of use per watt-hour of their tightly-integrated stack. This is the way forward. I'm extremely excited to see what Microsoft can do with Surface and Lumia brought under one roof.