PC's are general devises that do a lot of things. Sure, you can build a specialty machine that is a great game machine, but it can obviously still do email, spreadsheets, hacking, porn, etc.
A general device is almost never going to be as good as a dedicated device. Consoles are dedicated devices, they are made for playing games and not much more unless it is incidental like watching DVD movies.
However, consoles have a long way to go before they are good enough to replace a PC as THE gaming environment.
First, they have to be unlocked and not proprietary to the manufacturer who then holds the developers' feet to the fire as to content and royalties.
Second, they have to be integrated into the Internet easily or just as easily linked to a PC for modifications, updates, server control, and new content (and probably a bunch of other things I can't think of).
Third, developers must have the freedom to produce content for the consoles that they want to make.
The reason you get mostly lame racing content on consoles are:
1) It is designed for the quick fix and not for the serious racer.
2) The games must appeal to a mass market or the devs won't make enough on the project to pay the exorbitant fees required by the box manufacturer.
3) The box manufacturers would never allow access to their proprietary information willingly for a small, independent dev team for a number of business and strategy reasons.
Eventually, we will have dedicated gaming environments that are open and integrated with PC's and the network. You may use your PC monitor to play the game, or even use your PC as an interface device for the game system, but the game system will have its own dedicated hardware that is designed for nothing else but playing games.
But, right now, games consoles are still toys (albeit fun toys).