PC gaming's biggest problem is that it's been an enthusiast market more than a consumer market. There are still tons of gamers that don't know the difference between 2GB ram, and a 2GB hard drive, or 1.21 gigahertz, to 1.21 gigawatts. For these gamers being a PC gamer is nothing but headache and heartache. The don't have a will to learn about the PC, and probably never will. Before buying any PC game, or hardware most PC gamers do some research. "Is it compatible with my current hardware? Do I meet min specs? Any known problems?" Even veteran PC gamers have trouble with some games, and these are smart tech savvy consumers.
Currently PC gaming is in a good place. If you bought a high end gaming pc 2 years ago it's probably still well above recommended specs. Mostly because the hardware race has slowed cause the difference in new tech and old tech isn't really that dramatic of a change when it comes to gaming. This might be due to the economic climate, or just a natural order of things, but it's really helped out consumers who've been trying to keep up w/ the Jones' (AMD, intel, Nvidia, and ATI). Their hardware arms race is one of a few reasons PC gaming has driven away consumers, and developers.
Piracy is a serious issue for developers in this global tech age. While many tend to blow it out of proportion it's still something you have to consider when releasing on any platform not just pc. The DS, and PSP are two other examples of platforms where piracy seems to be a serious issue. On PC piracy is a problem because often the pirated versions of games are cheaper, easier to obtain, and easier to run. Imagine you're 15 years old and want a copy of Bioshock 2 for PC. First off you can't order it from an online retailer like steam since you don't have a credit card, some stores probably have it in stock, but you're 15 so you'll have to ride your, bike or take the bus. If you happen to get it, and it doesn't work on your PC you can't return it. You'll have to figure out the DRM, and if you have the knowledge to fix a problem with DRM you already have more than enough knowledge to get a pirated version which is not going to have any DRM requirements. Who can really blame consumers when piracy meets all their needs, and legit buyers are left in the cold. Steam might be an answer to that. While it's not cheaper than piracy it is much easier to get games on steam, and easier to run steam games than pirated ones. Consumers have repeatedly shown they will pay more when convenient so it's possible to compete with free especially with the shady pirate community, and the amount of personal information people keep on their pcs.