True, but what if, although I do think the analogy kind of falls apart there, Coke was allowed to dictate any change to the recipe? That's the situation Samsung would be in if they relied on 'stock' Android. Google would have a significant advantage simply because they control both the device and the OS (the latter IMO more important), and Samsung would only be able to compete by device.

And that's even assuming that Google doesn't 'leverage' its ability to control both software and hardware.