Are you familiar with GOG? It's a site that has this whole gimmick of selling only DRM-free games. Judging by their extensive game catalogue, a lot of developers and publishers are okay with releasing a DRM-free version of their game. I wouldn't say it has hurt their sales in the slightest. On the contrary, a lot of people (me included) prefer to buy DRM-free whenever possible, because DRM is just scummy.
Just look at companies who implement heavy DRM (blizzard and EA come to mind). Generally their reputation among gamers is not really great. I wonder if the two are related.