The sound of a shotgun chambering a round is a sound no intruder ever wants to hear!
That may be. But any intruder in my house will only hear the safety clicking off. I don't want to take any chances with fumbling the first (and possibly only) shot.
Many don't consider they may not be able to hold the shotgun upright when the need arises. If it's held with the port down when you shuck it the shell may well wind up on the floor instead of the chamber.