Well, what's wrong with Android? It's based on Linux and somewhat Open Source. It would be nice if there would be more compatibility between desktop Linux and Android, but that's something that could be accomplished without reinventing everything. Ubuntu in fact worked on allowing you to run Android apps on desktop Linux, but they abandoned that many years ago and instead went the same "reinvent everything" route that Mozilla tried and they will probably fail just the same.
If Free Software wants to stay relevant in the long run they need to work more on interoperability, portability and mobility. Back in the day there was a "many user : single computer" environment and cloning Unix solved that reasonably well, but these days we live in a "single user : multiple computer" environment and so far Free Software isn't really handling that all that well and all these "let's write yet another OS" efforts aren't really helping, as they are just yet another OS that it mostly incompatible with the devices I already own.