Actually, about the only people who honestly might benefit from a mag disconnect are patrol officers if they had combatives training to back it up. I mean think about it, sure they have retention holsters, but nothing changes the fact their gun is right there for the taking on their belt, and no one can be perfectly aware of their surroundings at all times. I remember reading somewhere that a fair number of officers are shot with their own service weapon.
Granted I still wouldn't want that feature even if I were a patrol officer, but I can't blame someone who does.
Anyway, some guns are in fact designed to be field stripped by pulling the trigger. If that makes someone uneasy, they honestly need more experience and the apprehension will go away.