It sounds to me like PC gaming is something people would need to stick with for quite a while until they 'get the hang of it'. To me (and probably every other long time PC gamer), it is just very simple to fix any issues that might occur when trying to run a game, maybe we have just learned over time all the 'places to look' and reasons for any issues, but for a console gamer trying to get into PC gaming, I can see where there would be problems.
But I honestly can't remember the last time I had any kind of issue running a game. I just skimmed my steam games list, and I have only ever had issues with 2 out of around 200 games, being Bioshock (games for windows live was messing up, so I just googled a way to play without it), and Need for Speed Hot Pursuit (EA didn't update the steam version, so I just activated the game on EA's download manager and it updated to the latest version).
Witcher 2 ran perfectly fine with me, around 40fps on high settings, it feels like it's getting a lot out of my hardware (Phenom II X4 955, GTX 470).
I feel like Valve is trying to make it a lot easier for console gamers to enter PC gaming (with ATI driver updates integrated into steam, and that big screen mode announced a while ago).
A lot of the problems I have heard about relate to things like Games for Windows Live, or Rockstar's login thing for GTA4. Programs like these that can potentially stop a game from running really drag down many games. It's obvious that Steam is the biggest digital download service, and the only way I see others being successful is if they don't require any software to run (which is why services like GoG, Impulse and D2D are relatively successful, and GFWL is ignored). But Microsoft is really pushing too hard, and I don't see them removing background processes from GFWL games, which would only frustrate console gamer's playing on PC.
I think the more you play on PC, the harder it is to play console games. A few months ago I bought Assassins Creed 2 for the PS3. It updated to the latest version, but there were horrible framerate issues, and the screen tearing was so bad that I stopped playing. I know the PS3 can do a lot better than that, after playing Uncharted 2, but there's no way the developer will fix any of those issues now, and it's not like I could upgrade the PS3 to make Assassins Creed run better. I checked online to see how many people were complaining about it, but suprisingly, not many were annoyed by it, so maybe it's after playing on PC for so long, video issues stick out a lot more to me.