I'm still mad that as a society, we basically let the idea of "sideloading" become normalized. Just the idea that the software you run on your device is subject to DRM is so inherently and extremely wrong, and yet it's just normal now.
So many other abuses of power in computing come back to that; to adapt Doctorow somewhat, there was a war on general-purpose computing, and we lost.
(edit: see replies below for important discussion of "lost," and why that might not be the best word.)
(We can fight that war again and win, but damned if it's not harder now that DRM is just the norm, and user-owned devices are the rare exception.)