At first, this threw me; I wasn't even aware that there was DRM on Steam. Well, of course I intuitively knew it, but I never associated it with the issues that people usually complain about regarding DRM.
I've never had the DRM get in my way... My experience with iTunes has been that when a bad bump on an airplane toasted my external hard drive and lost me every piece of legitimately paid for music and every legally purchased TV episode on it, I would never be able to download those purchases again. Steam, on the other hand, has let me download the same game as many times as I've found necessary, external to external, computer to computer.