One that I've heard is that you need rhythm to play. I don't see that being all that true, it's really just eye-foot co-ordination. The only way rhythm factors in is when you freestyle...
I think it would take too much time and effort to add in the little details for it to resemble an actual ddr game with the graphics and such. Plus I doubt the general audience knows what DDR is exact ...
I just caught the 'Malcom In Middle' spot, man does it look hilarious! It's not making a simple cameo like it did in 'King Of The Hill', it's getting an entire episode dedicated to it with Hal no les ...