I've been a Steam user for 8ish years now, and it's never once gotten in the way of me playing games. The only downside that I can see is that you can't gift old games to friends (or sell them), and they're very upfront about that fact from day 1. They just recently made a change that allows you to share game libraries with friends/family actually, so that small gripe is going away.
It's hard to have a real discussion about DRM because it's like religion to a lot of people, and many are quick to dismiss DRM because it's not perfect. Saying "DRM is fundamentally and inherently bad...but simply at what it is nominally intended to do" isn't saying that DRM as a concept is bad, but that the past/present implementations have been bad. Dismissing the idea because a few implementations have failed doesn't seem very hackerish :)
The core of DRM is: Creators should be paid for the stuff they create, by the consumers of their stuff. There have been plenty of misguided attempts at this, for sure, but I think you'd have a hard time defending the counter position (especially if you want to have a morality discussion RE: DRM and not just a conceptual one)