I was quite disturbed on a flight from PHL - BWI on Monday. It was the last flight of the day and, as is typical, we were a bit late for bags and connecting passengers. A gate attendant pulled the jetway away from the 757, and 5 minutes later an approximately 40 year old man walks down the jetway with a baby in his arms. It's a clear, clean drop right down to the tarmac in that situation. Major safety hazard. I can't believe they let him down. I saw the expression on his face. He was VERY angry. We sat there for another 30 minutes loading bags. They never reattached the jetway for him. I didn't understand that. I mentioned my concern to the flight attendant who said that they would not reattach the jetway. But I've been on flights where they HAVE reattached the jetway. Considering that it was the last flight of the day, and we sat there for thirty minutes, why didn't they let the poor man onboard?