This. I love CoD, and I usually wind up buying each one. Not on release, but I do own the majority of them now. Really fun shooters with solid online gameplay, and it does a different thing to games like Battlefield and Medal of Honor (which is basically BF3 multiplayer on small maps...)
I think I got it. If you grew with the arcade scene or even just enjoy arcades, your level of favor with FPS will be higher than the ones raised on the Game Boy and the N64 era of gaming. In short, if your first major gaming memory is platforming as Mario or opening a chest as Link, you won't like FPS nearly as much... As the stuff I like...
I think I just cracked the video gaming code.
My first major gaming system that I spent a lot of time with was the Game Boy on handheld and the Nintendo GameCube on console.
The first game I adored with every fiber of my being was Pokémon on handheld and The Legend of Zelda: Ocarina of Time on console.
Ask yourselves the same exact question and see if that matches up with your continued preferences throughout your gaming life.