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.
No, the carry-on is a piece of luggage that can be stored in the overhead compartment (assuming there’s room, hence the waiting in line). In addition you can bring a personal item (backpack/purse). It’s those bags being put up top as well where the dick moves come in since, on a full flight, there’s not enough space up there and the passengers who boarded before you have put BOTH their carry-on and personal item up there.