I think im a pretty normal gamer, and i think over the last years i bought 5 games and pirated something like 20. So my personal pirating rate is 80%+, but that doesnt mean i would have bought any of the games .. most of them were boring, but i brought 2 after i warez'd them. If i think back and count the games i loved and should have bought vs the games i bought, my lost sales rate is below 50%.
I'm kinda experienced in that pirating stuff, doing it since the good old isdn days, but these days with bittorrent and the pirate bay, pretty much everyone can pirate something if they dare.
DRM has never been any issue for me, in the worst case the crack come out a few days after the official release date (gasp!). A few years ago, when there was less pirates and just some simple copy protection, it took alot longer to find a crack. Ok, on Mass Effect with the fancy new securom it almost took two weeks to get a bug-free crack, but on the other hand, many who bought the game also had to wait ...
Sooner or later everyone, pirate or not, needs a crack for something: DRM creates pirates, from music to games to video. I remember trying to explain to my mom why she can't copy a CD to leave it in the car (and failing at it) ... in the end i just downloaded the album and she became a music pirate (sort of )
Anyways, i think the absolute mayority of game pirates are not against paying for a game in general (i have brought plenty of games myself), but against buying a bug-ridden, boring, unplayable game that is not my taste or doesn't run on my pc ( just the same for music and video ).
Even if DRM worked and prevents me from using a product, leaving me unable to decide if i like it or not, that definitly won't make me buy it blindly ...