I think it's funny that people consider getting up to change a game excersize. Somehow they think not having to do that will make them gain more weight.
"Oh no, now that these 4 seconds out of the day I would spend doing something barely mobile will be replaced with complete immobility...I'm going to have to diet in order to make up for the 3/10ths of a calorie I won't be burning off. I suppose I can spare to leave half a noddle on my plate of my spaghetti dinner."
Having a power button on a controller will not make you fat, it will not make your muscles atrophy, and liking the feature does not make you a loser, someone who hates excersize, or an inherently bad person. Don't worry.
EDIT-
Well, Zap, if it's wireless, it does have to be self powered unless you've found some way to shoot a stream of electrons out of the console to the controller in order to power it. If you're talking about corded controllers though you're absolutely right.