Okay, as I'm sure you know, Android is built on Linux, so saying something like Linux wouldn't work on phones is quite an odd statement. And Linux on PC's wasn't always "it just work". It's taken a long time and hard work to get it to where it is. And it's "just" code, there's no reason whatsoever that with a lot of sweat and elbow grease it can be a good user experience (see Sailfish OS). The desire and need for a non-Android OS has been quite low until recently.

I do agree that moving AOSP stewardship to someone else would be for the best and the easiest option for everyone involved (except Google I guess).