Actually if Samsung wants to be a player I really think they can't afford to be tied to Android long term. Too much control at Google and Google is another player and nominally an 'opponent' at some point. Of course their is "Android" and there is the stuff that Google puts around it. Watching the Chinese companies add value to the OS install has been instructive as well.
What Android has done has shown the component manufacturers some ways to expand their markets outside "known" players. Part of the challenge of making a phone is getting the chip vendors willing to sign off on giving you software to run their chips (weird I know).
My guess is that carriers want to be able to advertise to a captive audience, and in the US and EU, they can largely choose which phones their users buy; so killfiles as a feature are verboten.
What Android has done has shown the component manufacturers some ways to expand their markets outside "known" players. Part of the challenge of making a phone is getting the chip vendors willing to sign off on giving you software to run their chips (weird I know).