Another "doomsday scenario" is that a distinct market for FOSS hardware will arise, albeit much shittier hardware than what everyone else uses. Those users will become fringe and progressively isolated.
>>richar+(OP)
This is already the case for FOSS communications software and social networks.
In the past you culd use your FOSS client to commicate with your ICQ, AIM, MSN Messenger-using friends. Today, not using the official client will likely get you banned from the network.