You're giving up just becuase you can't max out a games graphics on games that are clearly designed for the next generation of cards?
For me I'm not getting into PC gaming just for the graphics but the gameplay, it seems to me that gaming has become more focused on graphical showcase then the actual game itself. Just like Sony at E3 2005.
I have fun playing UT2004 on low setting and just becuase you will only play 2007 on med/high or whatever setting you will play on your not going to enjoy the game?
Remember the formula
gameplay > graphics
But I do understand that if you buy today's top end it becomes yesterday news, but that don't mean you won't be able to enjoy the games with decent graphics.
If UE 3.0 looks so good now would it not still look great even at med settings?
In UT2007's case just cause I can't see the great detail on the guys face becuase I'm too busy jumping and shooting flak at them doesn't mean the game will look like crap. You won't be able to see the detail of the people in very fast pace games like UT because everything moves so fast you won't be able to notice very much except the textures on your gun/vehicles and the world around you. I could disable shadows on models, turn model textures to low and wouldn't affect much when playing deathmatch.
But in Oblivion's case you will see the detail in everything, but this also means that you don't need as much frames to enjoy it.
You can't expect to max out games that are specifically designed to push the graphical boundries of the video game industery.