By the way, the upstream Linux kernel supports the Nexus 5X! http://www.phoronix.com/scan.php?page=news_item&px=Linux-4.9...
And the bootloaders are based on fastboot pretty much everywhere I think? At least that was the case with the non-Google-related HTC phone I've had.
Android is the emblem and sigil of Tivo-ization. And Google was the key enabler of this. I get that this was successful - after all, "Android overtakes Windows as the blah, blah," is very successful. And maybe if Google had behaved ethically Android wouldn't have been the success that it is. Just don't give me any of the "don't be evil" BS. When threatened, Google was every bit as evil as Microsoft was at the height of the browser wars.
Have look at Redhat, how far got them requiring UEFI at server ARM boards. That's market, where the buyers have much more impact on the design than mobile.
Google's inept 'management' of the android ecosystem has left us with openness for hardware vendors like Samsung but not end users. Their design of android deprives end users of regular security updates that iOS users enjoy but also deprives them of the right-to-modify that licenses like the GPL were intended to guarantee.
I don't know what everyone at Google intended, beyond 'let's beat Apple', but the way android turned out looks awfully evil to me.