There are plenty of other reasons. Firstly, the cost of the hardware. Secondly, knowing that the game will perform properly out-of-the-box. Third, being able to play games on a larger display (37"+ monitors are becoming common place) while sitting down in a comfortable chair. Fourth, being able to play with friends gathered round.
The cost of PC gaming has dropped significantly in recent years. When you factor in the added $10-20 cost of console games, as well as other expenses like multiplayer fees and overpriced peripherals, PC gaming really isn't that much more expensive. However, it does require more tech savvy. You have to know the difference between a 9800 GTX and a 9800 Pro. In other words, you have to be willing to spend the time to sit down and learn about computers. It's not difficult and doesn't require any real skill or talent. It's simply a matter of putting forth the time and effort required. I began as a console gamer myself but I wanted something more, so I did what was needed to become a PC gamer. I read all the magazines I could, I checked out all the demos and shareware, I tinkered with my machine.
As to your second point, I agree. Knowing that your game will work out of the box is a big factor. However, it is also one that ties into the whole patience thing. A patient person will read reviews and message boards. They'll wait for demos. They might even pirate the game and test it that way. If you know that the experience will be superior once you get it working, that means you have a long attention span.
Your third point is valid. Your fourth point is arguable though. PC's can be a social experience. LAN parties are a testament to that. It's just that it's much more convenient to make consoles a social experience, even if it requires a tainted game experience. I can't stand playing in split-screen but many gamers tolerate it because it's much easier than hauling their PC's over to their friend's house.
PC gaming is a huge amount hassle than it should be. I congratulate people like us that actually bother putting up with it because the gaming experience is much better at the end of it but it's a huge amount more effort than it should be.
Yeah, it can be a hassle but our patience rewards us with better gaming experiences. Both the greatest strength and greatest weakness of the PC platform is its flexibility. It gives the more dedicated among us the ability to get the best out of our games. For those with short attention spans, it is a burden, as they desire instant gratification and are willing to compromise their experience to this end.
And the PS3 sales would have been much greater if they weren't released on X360. It's simple mathematics and isn't exclusive to the PC.
No, it isn't exclusive to the PC. However, PC suffers the worst. The 360 and PS3 are largely interchangeable and cater to the same audience. They have very similar hardware and peripherals, unlike the PC. The average gamer is still more likely to buy a 360 or PS3 version of a game than the PC version.