This is an interesting observation. It parallels something I have been considering in regards to the Rock Band and Guitar Hero series, in fact anything which fundamentally is not different from it's predecessor but which is continuously released. For example, the Rock Band franchise illustrates my point nicely. The fundamental game from RB to RB2 to RB:Beatles has not changed. Sure they updated the software with some tweaks (isn't that really just a patch) but the way the game is played stayed pretty much the same. The only thing that has changed is the music available. For those of us that play any of the music based games this is what really maters. I could care less if I am playing RB or GH, I just want to play the songs. I look at this observation about Steam in a similar way, all we really want to do is play the games. We could care less if it is Steam, XBLA, or any other service (as long as it works of course). Why not treat Steam (or the RB or GH franchise) more like a piece of hardware than software or service. Also, if Steam is just the most popular, and by that I mean most user friendly, way to distribute games digitally why not license the technology out to other companies which can then offer their own service with their own selection of games. Personally I used to do a lot of gaming on PC but not much ever online so maybe I am a little out of touch with the online gaming community but when I look around the gaming business, as well as the entire business world for that mater, I see old business models and outdated technology. Isn't it time for us to embrace these new technologies and start thinking outside of the box again? Digital distribution is the wave of the future and just as Netflix is streaming movies directly to a TV set with a little box, Steam will be doing the same eventually (PC or otherwise).
In response to another point that someone made about conflict of interest, the conflict of interest is a good reason to spin off Steam into it's own company.