Take my opinion with a grain of salt because I'm not an FPS fan and haven't been since I was young enough that the only games I played consisted of A) Doom I and II and B) Indiana Jones and the lost city of Atlantis.
Having now said that, I've played games for most of my life, and I basically got off the PC as soon as I got my hands on a console (the N64, incidentally, followed by the PSX and onward from there). While I absolutely agree that there is something to be said for the swifter and more accurate aiming of mouse controls, I dislike the idea of my experience of a game being limited by hardware.
I use my laptop for music, writing, and the internet. That's about it. It cost me a grand and it does these things very well. It runs at a completely acceptable speed, has only crashed once since I got it, and generally serves everything I need it for.
What I don't need it for is gaming, and I dislike the idea of spending an extra fuck-ton of money just so that I can keep up with the requirements of a game, or indeed the other people I might be playing it with.
Aiming is always going to be the biggest problem with console FPSs, but for a lot of people (or at the very least, for me) it's worth it to know that you're essentially all on the same playing field. The reason I'm not a FPS fan is that I hate multiplayer, and most of the single player campaigns these days can just go...sorry, I'm getting a bit ranty. I've been watching too much ZP lately.
Anyway, the point is this: consoles have shittier aiming, but they cost a good deal less than a high-end gaming PC, and have the benefit of knowing that if you suck, it's because you suck and not because what you're playing the game on isn't as advanced as what the other person is playing the game on. For some people, like me, this is enough.
Also, the best FPS ever, Perfect Dark, was on the N64 and subsequently released for XBLA, so that is where I'm going to be playing it.