I don't think this is a good example - the main problem with the FreeRunner turned out to be an unfortunate choice of hardware that turned out to be very buggy and dog-slow. This in turn made the device quite unusable as a daily driver mobile device, which significantly reduced the motivation of people to work on it.

Another contributing factor might have been the general lack of telephony middleware (no Ofono back then), which the FreeRunner distros basically had to build from the ground up (IIRC it was the FSO telephony framework).

Take the N900 for comparison - a reasonably open device running Linux with a physical keyboard that you can actually use to call, send SMS messages and use mobile data on a daily basis. As a result there is still an active community many years after Nokia dropped any official support.