Agreed, and well stated. I am not familiar with Steam, or Impulse, or any other DRM method to any qualifying extent that would make me an expert. As most here are not unless they have extensive programming and DRM experience.
I'd like to believe I'm pretty well-versed in many of the DRM methods because I tend to rely on filesharing when I don't have a lot of money or when I'm not sure about a title and it doesn't have a demo (and in both cases, when I do have the money and I feel the software is worth paying for, I buy it - even if I don't play it after buying it because I was done with it before.) I believe in supporting good developers (and that doesn't mean just mainstream developers.) I can say that I hate a great deal of DRM because it tends to punish legitimate customers and does absolutely nothing for piracy, and in fact I've avoided buying many titles due solely to Starforce and SecuROM, because I despise registry-based DRM. I try to support indie games when I can, and I like to buy games from developers that have a stated stance against DRM (such as Stardock, though they still employ DRM in the form of registration, it's just that it's not invasive at all.)
I think many peoples' opinions on what constitutes DRM are skewed due, in part, to manufactured ignorance. This is because of a divergence of stated and actual purpose- publicly, publishers will tell you that DRM is to prevent piracy (which, historically, has proven to a solution with a potency ranging from poor to nonexistent.) In actuality, it is designed to prevent second-hand trading. Registry DRM SecuROM (and Starforce I think, I can't actually remember the last time I saw a game with it) tries to prevent the user from burning a copy of the game, or using a burnt copy or virtually mounted ISO. Registration DRM prevents certain features (such as patching) from functioning, or the entire software package if it changes hands. Login prevents multiple users from accessing the software simultaneously. CD-checks force the user to prove that they own a physical copy of the game.
But here's the thing- I'm not entirely opposed to DRM that prevents resale of games, because I don't sell my games. And that's where people are running into problems, due to this skew. I am opposed to DRM that hinders a users' use of the software (CD-checks and SecuROM) but I don't mind Registrations and Logins. This is where you'll find the opinion skew- Steam users, for the most part, don't mind registrations and logins because they are the closest you can get to the convenience of filesharing and still support the company (beyond no DRM entirely, which is usually the realm of Indie games, Open Source software, and donationware; mainstream titles with no DRM of any sort are either rare or nonexistent; even Stardock requires registration to patch.) The opposition lies on two sides, generally- those who are against using Steam because they simply don't feel that it should be necessary to install a third-party program to run a game (which I feel is a valid viewpoint), and those who despise it because they either don't understand how Steam works (the ones who say that it "steals personal information," which is blatant misinformation based on their inability to understand the privacy policy) or that they are opposed to "all" DRM (but will generally support Impulse, despite it being nearly identical to Steam other than Steam being required to run in the background, or they will support CD-checks despite them being even more obnoxious, and only tolerated because they've been grandfathered in.)
If you had questions, I hope I answered them somewhere in all that rambling.
EDIT: Oh I forgot to address:
Steam does possess an "offline" mode. However, as has been stated more eloquently (or at least in more words) in the past, it is not the ultimate panacea. It can and does have issues.