People will not willingly buy a locked-down device over an open device, all other things being equal. So general purpose devices will not be made available, so that locked-down devices will sell.
edit: the only people who think that being locked-down is a feature are rationalizing technologists who indirectly profit from that arrangement. It's not even more secure. The methods used to control locked-down devices (namely constant network connections and cloud storage/control) are the most vulnerable attack surfaces we have, and the source of virtually all contemporary security disasters.
I sorely wish you were right, but the success of companies like Apple seem to indicate otherwise. I won't buy a locked-down device, but for every person like me there are thousands who don't care.
edit: the only people who think that being locked-down is a feature are rationalizing technologists who indirectly profit from that arrangement. It's not even more secure. The methods used to control locked-down devices (namely constant network connections and cloud storage/control) are the most vulnerable attack surfaces we have, and the source of virtually all contemporary security disasters.