What a lovely world you bunker monkeys live in.
You're obviously unaware of the large numbers of home invasions, murders, robberies, and rapes that are iniated by a knock at the door.
A prudent man or woman would not only be prepared for such scenarios, but prepared to prevail should they occur.
Likewise, a prudent man or woman would extend common-sense courtesies to others when at their door. This includes hands out of pockets, and standing several feet back from the door.
Crowding the door, or pretending (cognizantly or not) to have a hidden object, is asking for trouble.