This has to do more with Google and the Open Handset Alliance (OHA) and their terrible restrictions. A company can't distribute a phone with Gapps if they product Amazon Fire devices. Samsung even got shit for using Skyhook instead of Google for location services (Skyhook is still battling this in court):
http://penguindreams.org/blog/the-philosophy-of-open-source-...
that isn't exclusive to OP, though, of course - every other vendor I can imagine does the exact same to any non-hardware customizations they apply to the OS.