Google has made it very clear they are opposed to so-called 'incompatible' forks of Android, and that they consider pretty much anything not running Google's proprietary services to be 'incompatible'.
http://www.theguardian.com/technology/2012/sep/19/android-ch...
I think THIS was the issue, not the forked Android.
Amazon has a forked Android. Cyanogen has one.
Google has essentially taken over the ecosystem via their Google Play API. I know this first hand as my beloved Blackberry OS 10 was able to run Android apps. Now this is almost impossible as the majority of apps created in the last few years have hooks into Google's APIs and absolutely won't work without all of Google's hooks into your privacy.
I don't imagine roms that avoid GApps will be a viable alternative in a year or two either.
Microsoft has been trying to develop an ability to run Android apps on their phones, and it looks like they're giving up too due to Google's lock on the APIs.
If Microsoft was able to present a viable alternative, such that manufacturers could choose to use Microsoft's flavor of Android over Google's, it'd effectively wrestle control of Android away from Google, because Google would no longer be able to impose such strong terms over access to things like the Play Store.