There are a couple of points missing here:
Xbox 360/PS3 - around £200
PC good enough to run BF3 etc properly - around £750 to well over £3k
Plus, you need to constantly upgrade the damn PC as new games come out, video cards etc need replacing, at over £200 a go!
I have a high end PC, Xbox 360, PS3, Wii etc etc. I love them all and play all my FPS on PC, becuase of the keyboard and mouse control.
BUT...
I prefer the easy access and lower overall costs of the consoles. So if there is a way to use my preferred control method on a console, I will take it. This saves me money as I dont have to keep lining Nvidia's pockets each time a new card is released and my new game runs at a slideshow.
I really think the console market is missing out on stealing a lot of PC users. There are many thousands of PC gamers that would jump to a console given alternative control options. If Microsoft/Sony etc were to bring out a keyboard and mouse control system, they could police it and only allow it on certain servers. This would help with the game levelling.
I agree its easier to play with a keyboard and mouse, this is why I want to use it, but I also understand the unfairness it may create. I just feel rather than flaming each other, we should look at finding a long term fix as the problem is not going to go away.
Just my 50 pence worth!