I think you still need to install Steam client and it always has some level of DRM. As far as I know, in order even to play the game, you need to run the Steam client. That's already DRM for me, unless I misunderstiid their requirements. I'd prefer to work without any "clients", just using some installer / package / tarball (like Humble Bundle does, and how GOG does for Windows games).
Surely DRM is not limited to preventing CD copying. It means any kind of restriction on managing the data (like copying it around, limiting the amount and/or period of installations, requiring to connect to special server to use it and so on).
I call it DRM as an inclusive name. It's DRM for me.
DRM stands for Digital Rights Management which is about validating an installation by an outside authority. It has nothing to do with being able to copy the data. You can do that all day and get the perfect 1:1 copy but DRM will still thwart the installation unless re authenticated.
I think you still need to install Steam client and it always has some level of DRM. As far as I know, in order even to play the game, you need to run the Steam client.
If this is a strict requirement, then I to agree with you.
But is that really true? Isn't it possible to use Steam for distribution only (if the game company intends to),
so that you can copy the game-related SteamApps folder to another computer and launch it there
without Steam (and 3rd party DRM)?