Why does moving a couch through a large window seem to be a dreadful thing to...

[Mister Answerman]

...do rather than thru the door? A tenant at the rooming house moved a new bed into his room through the front bay windows (almost the size of half a door when opened) and the landlady thought is was a "shock, horror" thing to do. Why?
It was a couch that turns into a bed when the back is levered down