Sure, it may be cooler to watch videos by waving your arms, but still... buttons are more accurate and faster to use. What's wrong with using the controller for controls?
Nothing. Sort of like eating sushi with a fork...may be more practical, but you will not rack up any style points in doing so.
I've tried eating sushi with a fork once in a while, usually when I take some home and eat it later. It always fall apart for me. I think the chopsticks are more practical.
"If you can, help others. If you can't, at least don't hurt others." -- the Dalai Lama