Because most banks are douchebags. Banks have lines under the assumption (and hope) that their services will be quick. Often-times banks are overconfident and quite deluded and arrogant. Hospitals prefer patients to sit in comfortable seats because hospitals can be scary. When someone goes to a hospital its often because something is wrong or you're in for testing to see if something is wrong with you. Hospitals and a hospital visit can equal death or bad news to someone. They want you to be comfortable because hospitals anticipate that you are anxious, in pain, or about to receive some bad/not so good news.