I don’t answer the door either. Maybe during the day, but definitely not at night. If it were someone I knew, they’d have called first. Nothing is as important as your personal safety. I’m sure that “I thought he was telling the truth about being homeless/his hurt puppy/his wrecked car/the charity he is campaigning for,” is a great comfort to women (or men) who opened the door and lived to regret it.
A year or so ago I had fallen asleep in the recliner near my front door and awoke at 2 AM to some rustling sounds. I went to the peephole and it was a drunk-looking man trying to open my door. I grabbed the closest heavy object, which happened to be a rock pick. (My toolbox happened to be near the door.) When he started banging I shouted at him to go away. Then he started mumbling some nonsense that I knew who he was and told him he could come over. He left when he heard me talking to the 911 operator.