Google has been pushing the envelope with every new Android edition, whereas Apple has been trying to play catch-up with their iOS (their latest achievement - notification bar, a dysfunctional one, compared to Android's) and trying to sue everyone out of business for stupid patents that get invalidated every day lately.
Apple's only advantages were:
-plethora of apps , now irrelevant because devs have caught up pretty fast
-hardware - they used to hold the crown of luxury handsets, now left behind not only by top tier Android phones and tablets, but also by the new generation WinPhone 8 handsets.
Of course, nobody can sink Apple better than Apple themselves, with the latest blunders in terms of both hardware and software they did put up lately. To be honest, every manufacturers has problems/bugs, but only the ones that claim to be perfect are the ones that get the scrutiny of the masses.
Last but not least, people enjoy diversity and enjoy having choices to make on their own, not choices to be made for them by someone else, be it a person or a company. Especially when that person/company behaves like the schoolyard bully.
Comparing Apple to BMW - that only stands when you look at the option to dump the BMW and buy a Ferrari or a Lamborghini or an Aston Martin. Those guys sell even fewer cars than BMW, but I would pick one of them every day over a BMW. For instance, why settle with an iPad Mini when you can get better specs on a Nexus 7? Same question for iPad vs Nexus 10.
It's all about choices, that's all. For me Android is way more functional/logical/easier to use than iOS, which I find clunky and old, backwards and uninspired. Others might just be too heavily invested in iOS to look back and change ways. If/when WinPhone gets close to the amount and variety of apps that the other 2 OSs are enjoying, I might even consider Windows phone instead; who knows? I keep my options. Too bad that many iOS customers are too brainwashed to realize they even have these options.