For gamers:
- Many more games to choose from / You don't have to limit yourself to one console and its games if you can't afford another one. (PC has the most genres and the most games)
- You can play online with your friends, no matter what console you own. (Now with valve some games can be played across mac and pc)
- More freedom to find your style of gaming and play the games you like. (You can use keyboard and mouse, one of many third party controlers)
For developers (and publishers too):
- A much larger userbase without the need to develop games for several platforms (or port games) / More sales. (Far more PCs out there than any console)
- Less risk when creating new IPs. (Far more independants and indie devs on PC)
- More controllers that need to be supported.
For hardware sellers:
- More competition in the hardware sector.
- More competition in the online sector. (online gaming on the PC has many of the features of live if not all and is cheaper)
- More customers for their online services and games (potentially).(again far more PCs out there than consoles)
How does the PC market not meet what you want? I think all you really want is to have sony, MS, and nintendo publish all of their games on the PC
