Believe me, it happens.
I had an emergency evacuation with an engine fire on the ground and instead of running for the exits, people were popping open the bins to grab their huge suitcases they stuffed tightly in the overheads.
Normalcy bias. The whole country is experiencing it right now. One of my friends had a gate evacuation where the cabin filled with smoke during boarding with the door open. It was something electrical, if I recall. They had one pax who refused to leave his seat. He kept saying, "I have to get to New York!" Finally the chief purser got right in his face and screamed "This flight is canceled!! It is not going to New York!!" Which finally got him out of his seat.
Fortunatley I never had to do an evacuation, but his does not surprise me in the least. People and their crap.... Grrr! My thought was always what would happen when a slide busted because of some guy and his stupid golf clubs.