BmPilot21, I fully agree.
A locked door, strong enough to withstand a bad-tempered hijacker, provokes violence towards flight attendants and pax. Who of you wants to be the first pilot landing with only the flight crew still alive? Then there is the possibility of the pilot having family members on board, next in line to be killed unless he opens the door... how long would that door remain closed?
It has been the policy - or actually law - in the US for years (if not decades) to keep the door closed. Did that stop or even just stall the hijackers on any of the four planes? We all know it didn't.
Erik.