Name: G.I. Jonesy
There are other reasons to modify the base video settings. Brightskins, higher fps, removing of smoke-trails... all of this stuff makes a difference, but it's about more than just that. Depending on the visual aspects of the game, it can feel many different ways to you, as a player and as a spectator. Even if you have perfect 125fps, the game can feel slow, or boxy, or unresponsive, or imprecise. FOV alone can make the game seem faster or slower (raise the fov to make it seem faster). I know from personal experience, the visuals can make or break a game... and the visuals i'm talking about are usually capable of being modified within the existing game structure.
The best example I have, about what i'm talking about, comes from ut2k4. I never liked the game. The movement and weapons didn't feel right, and I didn't care much for the graphics themselves. But then, for some reason, years after I discovered how much the game wasn't for me, I reinstalled it, modified the graphics (with no modding or anything, just the basic tools available), and suddenly, the game became enjoyable. I played it a fair amount after that (with bots), and the movement never bothered me again, and neither did the rest of the game.
I would have to wonder, how many people are like I was with ut2k4? They go into Quake Live, and they so profoundly dislike the game, only because of the video settings, they decide never to play or watch it again. And how many of them, if they could only change the video settings like I did with ut2k4, would then enjoy and play Quake Live like I did with ut? And if simple video-presets were available, for them to sample the different possibilities, how many people would never skip years of playing and watching a game based exclusively on a set of easily changeable video settings?