DRM is restricting your personal use of what you own.
"OK, you've bought this house, but you can only have one bed, one table and two chairs in it. Oh, and you can't plant flowers in the garden. Nor can you maintain the flowers that are already there. No DIY, either. And you can only open the door for the next week, after which you have to pay subscription charges to get out and come back in."
Saying DRM is only bad because of what you use it for is like saying nuclear warheads aren't bad unless you blow stuff up with them.