The seats are assigned. People have been standing in line for 15 minutes now. Why on earth would anyone want to stand there, when they could just sit and wait until the line clears?
I understand wanting to get off a plane ASAP, but boarding? You just end up sitting on the plane, waiting for everyone else to get on.
I used to wait until the last minute to board, until the time I had to put my carry on bag at the back of the plane and my personal item under the seat and ended up being the last person off. One of the more uncomfortable flights I’ve been on.