Cheap 'poorly supported' Android smart phones with Linux underpinnings provide some licensing income for Google. Google I think also provides some funding for Mozilla. Firefox OS would potentially undermine Google's Android OS, the way Mozilla's free Let's Encrypt service is undermining over priced and deceptive SSL certificate vendors - which to me is a GOOD thing.
Me thinks Mozilla Firefox OS has a rather large addressable market for free / low cost smart phone and TV's that Google would rather get licensing fees for. Expect there is a memo from Google to Mozilla about withdrawing Mozilla funding if Firefox OS becomes a viable threat to Google Android licensing.
I would like to see a viable mobile OS besides iOS and Android. Browsers and connected apps are the killer use case for mobile devices, it really shouldn't just be Apple and Google, I think eventually some form of mobile OS that's essentially free will emerge. Maybe RedHat needs to get into this space with Fedora mobile then?