Some of us knew this 30 years ago

Situation is different from copyleft, because saying "use copyleft everywhere" is a tough proposal for those who can't come up with working business based on that (let's say it's hard to sell a game which is 100% open source including artistic assets). Business models which work for some open source projects don't work for every possible product.

DRM however is different, since it has completely no logical reason to exist, literally in any product. Therefore it's completely reasonable to propose to drop DRM everywhere.