CS2 came out during like Peak DRM, and Adobe has refined their efforts for the better since then. Creative Cloud licensing, for example, only checks on your subscription once a month. This whole thing is just a matter of dealing with a dopey legacy. These years later, positive user experience has trumped the strictest rights management.
The Mac App Store and Steam for instance, provide pretty excellent experiences. The more interesting conversation, particularly with the Mac/iOS app stores is the commoditization of software, reducing the impetus for developers to refine and build on a thing someone has already paid for, and either give free upgrades or provide add-on purchases. It's not an environment that supports grand upgrades or iterative product cycles, the exact kind of thing that gives us great professional tools like Photoshop.