The iPhone's got a lot of classics that I know we all love. Shooters and action games that control with sloppy touch virtual buttons on screen that you have to obscure with your fingers to interact with and can't actually feel (I can play a real video game without looking at it.) It's got motion controlled racing games, which I'm sure we all love. And if that's not enough for you, there's always classics such as Doodle Jump and Mega Worm!
It's about as much a game console as a handheld device with access to an internet browser and Flash would be. Sure, I'll play a game once in a while on it, but they're actually more like minigames. If that's truly your stance, I hope you greatly enjoy playing your games with a capacitive touch screen and an accelerometer.
Though I don't really remember being able to play Mario, Pokemon, Zelda, Final Fantasy, Professor Layton, Tales of ***, Metal Gear, Kindom Hearts, Persona etc, etc, etc on an iDevice. (I'm counting PSP and DS games)
I wouldn't use it at all if it didn't have additional functions (Which the RAM and processing power gets hogged by) that it can also do. They iPhone is massively overpowered (And nice and overpriced to boot) because it has to run everything at once. Dedicated game consoles have the potential for far better games because they can devote all their resources to the game instead of the OS and background processes. And they also have controls. Which are nice.