The same people who buy specialist wheels for their XBox when the same thing exists for PC's.
I missed out on a gameseat, 360 wheel + pedals(gold plated pedals no less!!), gear stick and handbrake setup on eBay recently. Total outlay for this kind of kit is 500.

Checkout this site to see how serious the Car sim crowd are about their console racing
http://www.playseats.com/

We can't rule out consoles as viable replacements for PC's in the future. Game manufacturers like that standard platform to work with. A PC has a multitude of hardware configurations that can cause all sorts of problems with games. A console is uniform across the board. A problem found and solved on a console is a fix on every single one, not so with a PC.