I disagree, at least for FPS's. It is way easier to point and click than to kick-ass in FPS's with a controller. Also, with PC's, the playing field is not level. Better computers, better monitors etc. gives one player a significant edge over others. Not to say that PC gaming isn't grand, it surely is but the skill issue isn't valid in my humble opinion.
FPS's are total shit with a controller. No serious FPS gamer would use a controller by choice. There's a reason there's autoaim in almost every console FPS and there isn't in PC FPS's. There's a reason the original Halo was originally going to be a cross platform online shoot em up but they then ended up canning it. People using a mouse and keyboard were abusing anyone using a controller with such utter horribleness it would never be fun for those using a controller.
Now, controllers are fine interfaces for certain kinds of games, but certain other kinds of games they are complete shit. FPS games are one of those types of games. MMO's, RTS's etc as well.
Platform games? Sports games? Now you're talking console territory/controller territory.
Also, for me, I will probably just get a new video card and another storage drive for my PC.
As far as level playing fields go, no doubt, some folks will be at an advantage on PC because of the choices. But for most PC games these days almost any computer can run anything recent (my computer is 5 years old and runs everything current, and it wasn't a kick ass machine, just a solid one back in the day). Comes down more to your interface tools. For example it's a huge advantage to have a 120hz or old school CRT monitor for old school shooters. CRT's are still the best, but harder to find and a PITA to use due to sheer size/weight.
And of course you need a proper mouse as there are a lot of total shit mice being made these days. Pretty much anything with a laser is a pile of crap if you're a serious FPS shooter fan (relatively speaking of course) due to inherent bugs in all the various sensors and flaws in the physical design. More DPI isn't necessary for almost anyone as you can only have so many dots on your screen in the first place. Just marketing gimmicks. People using 5200 DPI have shit aim for example because they can't do pixel perfect shots (totally impossible physically).
Anyway I could talk about this stuff for a long time but probably not many others are interested.