My argument was that DRM _could_ be used in such a way to negate most of the experience issues that people have. The objections that the author makes are valid

My argument was that DRM _could_ be used in such a way to negate most of the experience issues that people have. The objections that the author makes are valid in the implementation, but it is possible that it could be implemented another way. It's probably true that DRM will never be implemented in a different way because DRM is about power, control, maintaining monopoly and fighting technological progress. But there is a difference between the objection to the DRM ideology and the DRM implementation.