As others have said, convenience can and will trump DRM concerns, assuming a few things:
- * The DRM is "in the background" and reasonably unobtrusive. Basically, it has to do none of the things that UbiSoft does.

* The price is right. If the item is in the "impulse buy" range (roughly $5-$15 or the equivalent) and not $60, that makes a huge difference to a LOT of people, especially with the way the economy of many countries is right now.
* The ease of downloading and installing the game when you buy it from the DRM option. In this case, Steam makes it stupid-easy to install and play your game after purchase, usually giving you a "Play Now!" button within 2 minutes (unless the game is enormous and the download takes longer).
* The Developers don't shove the DRM in your face and harp on and on about the evils of piracy and how they're going to stick it to said pirates by punishing their paying customers. In real life, this only makes the pirates try harder and makes a certain segment of your potential customers reconsider pirating your game vs. buying it.
* Last, and possibly most important, the relationship of the Devs with their potential customers. Devs that are transparant; that at least appear to listen to reasonable feedback; that actually interact with their community (posting PR Approved Corporate Speak news items that never get followed up is the opposite of this); and that give a feeling of empowerment to the consumer ("It's your money that makes this all possible, thanks a ton you guys!") are the Devs that are going to sell their game.
A lot of people - myself included - make a point of pride to say, "I bought this game because I want to support this company and/or this kind of game." If you make yourself likable and your DRM isn't ludicrous, I'll happily give you my money. On the other hand, the "AAA" industry has garnered so much ill-will from their consumer-punishing actions (Ludicrous DRM, bullshit DLC, treating consumers as throw-away piggybanks, etc) that thoughts of visiting Pirate Bay vs. shelling out $60 for their games - and therefore saying that the shit they are pulling is A-OK - no longer trigger my Guilt Reflex.
On the other hand, pirating a game like Terraria or Bastion or Legend of Grimrock or Defender's Quest is nigh unthinkable, because I know I'd be directly contributing to the possible demise of a company that has built a game (or genre) that no longer gets put out by the AAA industry and, for the most part, caters directly to me.
I'll put up with Steam's DRM if I'm getting some piece of mind out of the deal. And again, convenience counts for a TON.