But how much pick is extended is part of the mechanics! Too much pick and it's either poking below the strings, which is wasted motion, or your hand is too far from the strings. People use ramps when playing finger style to stop your fingers from extending too far past the string plane, though if they do that's bad technique IMHO. But this is the same idea, you don't want half the pick poking below the string plane.
Plus the more pick that is extending from your hand, the move leverage there is for the pick to bend in useless directions. It's the equivalent to playing with your fingers with a half inch of plastic taped to your fingertips. The less pick that shows, the stiffer it is.