When you think of it, it was stupid devising a system whereby a captain could be denied access to his flight deck.
The one key person you want in charge in an emergency,doesnt have access to all of his aircraft.
More of two persons, remember LAM 470 where the captain locked the FO out and killed all on board by crashing the plane?
Interestingly enough some high ranked security officials in germany are now talking about removing the door again as the safety case is not as easy and one dimensional as originally thought.