To ask this question in another way, if you buy a physical disk can you bypass the drm? No. Not legally.
Heck, when half life first released as steam only I was fairly pissed. I didn't like having to login* to play my games, or downloading bloatware onto my pc. However, steam is fairly unobtrusive, and they do offer some ease of use. CD gets scratched? No problem, game has a new patch? No problem, steam can find and install the latest** one for you!
*Yes, I know of the offline feature, I also know it turns itself off at the damnedest of times, to the point I don't bother anymore.
**The latest patch thing really does annoy the hell out of me in games like fallout. If you have played any previous installments, you know that sometimes the most current patch is a bug ridden piece of garbage.