The reason is money comes from the consoles. Plain and simple. And I'm not sure for the X360, but PS3 developers are become more and more efficient in their programming. Take a look at Killzone 3, Uncharted 2, God Of War 3 and Heavy Rain. Because they are so limited, and they ONLY have to focus on ONE system, they can develop techniques and optimise heavily. For example, in God Of War 3, they use an anti-aliasing technique know as MLAA. Instead of relying on the GPU, it relies on the processing power of the PS3's CPU.
Don't bash consoles because you think a PC is better. No doubt it is, but when developers can't optimise due to so many different systems and hardware configurations, it will take PC game YEARS to move forward in how they look.
You guys also seem to be forgetting WHY you play games. It's to have fun right? So what does it matter. If it doesn't look like arse, and I haven't seen ANY game look visual unplayable for years, then just have some damn fun with the game! That's the whole point isn't it? If you want to look a graphics, then download programs such as Cinebench and stare away all day, but I'd take a PS3/X360 over a PC if it means having more fun.