That's true for OKW, where the living/dining room is much larger than the bedroom.
But that's not the case for the other
DVC resorts at WDW. At those resorts, a studio takes one rectangular hotel room "bay." A 1BR takes two. And a 2BR takes three.
There's plenty of floor space for an aerobed in on OKW living room, even with the sleper sofa open. At the other DVC resorts at WDW, that's not the case. (I would guess a single aerobed will fit, but it would be tight; I don't know abut a double.)