i love my 360 but to say it's superior to a high-end PC is hilarious, it's horses for corses. the console is great for some stuff namely sports/racing games but for FPS and RTS anyone who prefers a console either can't afford a decent high end PC or is delusional.
The preference could also be to do with the fact that a lot of FPS games are either not released on the PC or they are delayed by quite a few months, COD2/3, Halo 3 for example.
It's also about choice.
I for one could spend as much money as I want to on a PC and I used to throw bucketloads of cash at my rigs.
Nowaday I just can't be bothered paying in excess of 200 quid for a graphics card every year for a platform that has a handful of releases each year.
There is also the fact that everyone bangs on about the latest PC game only to find when it's released it's buggy and requires patch after patch to get it working properly under an increasingly bloated OS.