The community got fractured when the N9/950 did MeeGo Harmattan. This was a continuation of Nokia's Maemo OS that was based on Debian, but they just called it differently when they announced a collaboration. Nokia and Intel started a 'merge' called MeeGo (based on moblin and fedora). Nokia never actually used this in a device as they signed the famous partnership under Stephen Elop's guidance standing on a burning platform.
Sailfish is a successor of this actual MeeGo work that was done and therefore had an uphill battle. They never got the same traction as Maemo (or even Mer), so I never called this a successor of Nokia's work. Nokia created a community with developer conferences and handing out devices. Jolla couldn't do this ... and therefore remained niche.
My N900 with Maemo was fantastic. It's still working Just Fine, mechanically as good as when new (the Mercedes-door feeling sliding keyboard, for example), the only reason I'm not still using it is because it only supports up to 3G, and that isn't available anymore where I live. Such a nice phone. I could easily make Debian packages and install them, my minicomputer emulator for example.
The MeeGo transition stopped it for me, and Stephen Elop's burning-down-the-house strategy killed everything.
I have all of the NIT devices, but found the N810 the best; great keyboard, large, thin... but unfortunately no 3G. N900 is second best; great camera and nice User Experience
Sailfish is a successor of this actual MeeGo work that was done and therefore had an uphill battle. They never got the same traction as Maemo (or even Mer), so I never called this a successor of Nokia's work. Nokia created a community with developer conferences and handing out devices. Jolla couldn't do this ... and therefore remained niche.