Who the hell thought the buttstock was the best place to put the action switch on the M4?

I just don't get it. Even the AR 15 didn't have a problem with this. The switch is right on the side of the receiver on the civilian AR 15. Did the military think that putting the action switch on the buttstock would somehow get around the need to keep off of the receiver? Because it's not going to. And worse, it will tend to get a lot of debris and dirt in the switch because the buttstock is closer to the ground than the receiver. So that's what they did here.