What is important for a phone platform is what's on top, not what's on bottom. Android can compete with iPhone because of the high level stuff Google provided--the Linux at the bottom is pretty much irrelevant.

Most Linux phones, other than Android and WebOS, run crappy top level stuff written by the device manufacturers. Rarely, a device manufacturer does come up with something that is not crap to put on top of the kernel, but even then they can't compete with iPhone because they lack the infrastructure, like app stores that can attract significant developer interest.