If you're reading Cory Doctorow books and blogposts, that's exactly what "they" are working on and the part of the population that cares about this may be a lot smaller than you think.
I can see more devices like iphones being sold and locked down, but I can't see open computers not being sold anymore, not so long as there are companies and people with a will to make them. Look at System76 as an example.
Most ISPs don't care.