If they moved the air conditioner, where would they put it? To remove it off the roof mean either hanging from a wall or reset in the roof (which means the unit is actually inside the camper, maybe boxed in with a decorative cabinet, still, it would be a head bumper!
Under the trailer? Inside a jack knife sofa like some furnaces are installed. Then you have all the noise of the air conditioner actually inside the "box".
However, with today's technology and creativity, I WOULD think someone could design a more sleek shaped air conditioner, even if it had to sit on the roof.