Typedef, I had the same initial thoughts as you did, but my perceptions radically changed when I started getting into the game.
My main gripe against this game is its total lack of optimized code. The highest resolution at which I can play the game and still use FSAA is 1024x768. Anything higher with FSAA and it absolutely chokes. And anisotropic filtering? Forget about it. I wish Rockstar had taken some time to more tightly code the game.
Technical complaints aside, this game has been an absolute blast to play. I even have fun loading up a game, cheating up some weapons and just running around destroying anything and everything that gets in my way.
Is this the best PC game ever made? Hell no. But I will say it's the most fun I've had with a PC game since probably Half-Life and I'm sorry to hear you didn't enjoy it.