And yet, there is a pretty intense car aftermarket (minus the now sudden shift to having DRM on engine components). I think you are conflating "able to be modif

And yet, there is a pretty intense car aftermarket (minus the now sudden shift to having DRM on engine components). I think you are conflating "able to be modified by the hand of the owner" with "able to be modified at the direction of the owner": the intrinsic complexity increase leading to the former sometimes being unrealistic doesn't imply the latter is as well... my mother didn't build her kitchen cabinets, but she definitely directed the process, and she did not need permission from the company from whom she bought her house.