The thing is, in my parents situation, they do play video games. They loved the Atari 2600 and still get it out from time to time. If they see a familiar arcade game (something from the early 80's usually) they'll put a few quarters in it. Like I said before they go to casinos and play video games there with touch screens.
Beyond Pacman Vs., I can't think of a single new (arcade compilations don't count) Gamecube game I could get them to try. Its not just about the controls, but about the complexity of the game. I mean yes, the D+pad was a conceptual leap for them over the joystick, but I think with a lineup of software that didn't have such a learning curve they would've given it a try.
The home video game industry lost a significant customer base between the Atari generation and the Nintendo generation. It didn't really matter for awhile because those people had young kids to spend money on games for anyhow. Now that their kids are grown up and moved out and they are approaching retirement age, maybe its time to get them back.
Remember before you freak about "no buttons" that Pacman, Bubbles, and Robotron were all buttonless.