Many years ago I remember flying on Piedmont Airlines 737-200's with built-in air stairs. At small airports like LYH (Lynchburg, VA) there is no jetbridge so the stairs would come out of the plane and people would walk up or down the stairs.
Since then people have gotten quite lazy and this is why we have to sit there on the plane for an hour waiting for a gate. I think it's ridiculous.
I would rather go up and down the stairs and ride on a bus than wait even five minutes for a gate.