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.