You must not play crucible much if you have never seen anyone running around the map shoulder charging every one in their sights. You must also not use shotguns very much either. Also have you ever used throwing knives? They can be I saintly difficult to land a precision hit with and if you miss, you loose the charge. Even still, if you land a precision kill with a throwing knife on death, you don't gain the charge back even if you have the perk active.