Nike says Android has too many devices and varied experiences.

From Droid Life:

Olander also tossed out the there are too many devices, and the experience is the most important thing, so we’re focusing on iOS card. Look, Nike, we get it – there are hundreds of different Android devices out there, many of which are terrible. And sure, the experience on those may not be as good as it is on others, but that doesn’t mean you ignore the entire platform. We have already seen companies hand-pick select Android devices that they know their apps or accessories will work best with. Why not start with the Galaxy S4 and HTC One and Moto X? You can fine-tune the experience for those, and then slowly branch out to others if you want to. But ignoring the entire operating system because 200 phones has overwhelmed you? Come on.

I can't say I disagree. I think Google needs to exert more ownership of the platform through the Play store. Samsung and Amazon are creating their own experiences and seem to be distancing themselves from the Android community at large. I've been running custom ROMs since the very beginning and love my experience through that but a lot of skinned Android versions have a crazy different experience and can throw off devs.