That's an oversimplification. Hardware/software integration is complex stuff. In this case, Google's code works fine on other hardware, just not the _new_ hardware introduced by Apple. Now Google must change their code to accommodate that new hardware. This tail-chasing will always happen.
A lot of people are using it without even realizing it. I've spoke with a number of people for tech support that claim to be using "Internet Explorer", only to find out that they unknowingly switched to Chrome at some point without realizing it. A lot of people are drones when it comes to this stuff. And Google has been very aggressive about pushing Chrome onto people.
If I read between the lines, you seem to be basing Apple's *success* on market share by unit. That's not how they succeed. They succeed by delivering the best product they can with healthy margins. Tell me again how they are doing? ;)