It's not just some unfounded stereotype that video game controllers have gotten more complex over time, just look at this fantastic chronological illustration.
The controllers are offered in proper scale with each set of hands sized identically. And we see, while controllers have gotten more complicated, they've also grown larger—though we look to have peaked back in the last generation (if you discount arsenal of peripherals you'll find in Rock Band or GHIV).
One trend we found interesting: The ill-fated Atari 5200 represented the early height of how-many-buttons-will-this-thing-fit engineering. And I don't think that it was before two successful generations of consoles later that the arms race picked up again. [Chewing Pixels via Offworld]