To go further, any competition to Google and Apple are killed in the cradle by developers refusing to support their platform.

I think it's a bit more complicated than greed. Remember that the only mobile development shops in town are iOS and Android, and they're both run by tyrants. There are millions of developers who only know mobile development. Giving up their skillset to learn a whole new profession is difficult.

Your criticism essentially boils down to "Too bad human behavior is the way it is". Sure, I agree, but it's pretty unactionable.