Earlier quoted context omitted.
Or to look at it another way, they're perfectly happy to let you stand in a queue, outside, on the runway, in the cold/heat, waiting for them to unload/load the plane that has just landed and is often already late.
My personal favourite is Ryanair in Brussels airport. Ryanair generally use airstairs, and, as you say, often queueing outside. Brussels airport doesn't allow the use of airstairs. So Ryanair found a solution to be appropriately annoying; you get on the plane via a jet bridge... from an isolated building which has to be reached by bus, and which has no inside waiting space so you still have the opportunity to queue i…
Decided to head down and work out why, only to get shouted at by a very angry staff member as they wanted to depart early....