The open source community is terrible at UX, Android is the first usable mobile OS based on linux with a good UX and I'm typing this from my Ubuntu laptop. Second, Android is already available as open source and there are a few open source distro, they are not thriving. Finally, we're all greedy so let's not be judgmental here :) https://www.youtube.com/watch?v=RWsx1X8PV_A