Well, I can either play CoD4 with crap low resolution graphics, horrible pop-in, distracting blur and a joke of an auto-aim feature, or I can play it properly.
People harp on about the power of the PS3 and the 360, yet games that are on both PC & console, look noticeably worse on the latter. This applies to every single multi-plat game under the sun.
Consoles are cheap, and developed to cater to the majority with simple control interfaces. So you lose a lot of the complexity of both the gameplay and the graphics. Unfortunately, as console numbers grow, and the PC market declines, an increasing number of people are being forced to resort to the cheaper alternative as that's where all the software is going now.
It's a damn shame. We won't see something as complex as Deus Ex or Eve Online on consoles, and we never will (The PS2 version of Deus Ex was extremely castrated and neutered compared to the PC version because of the prohibitively limiting aspects of the control interface).