I've definitely bought games over Steam that work offline. In fact the only game I've had a significant problem with was Heroes of Might and Magic VI, and that

I've definitely bought games over Steam that work offline. In fact the only game I've had a significant problem with was Heroes of Might and Magic VI, and that was because of Ubisoft's DRM/uPlay platform and the vast quantities of bugs (even 2 years after release!). I think you have a good point though. It's the 'sugar', not some objection to DRM or always-online gaming, which keeps me using Steam. That and their support for indie developers, which is quite heartening for me.