> Developers aren't going to develop for five slightly-different ecosystems

The point, perhaps, is for one to emerge as the prominent choice, the correct one. Diversity however has its own value.

I wish Android manufacturers contributed to AOSP, so that it would still be one ecosystem, but with shared ownership. But I guess it's more profitable for all of them to let Google do it on their own. And it sucks for the user, because we have to live with Google's decisions.