It should not be so noisy that it bothers you. There must be something that isn't quite right. If it is a furnace, it should not cycle on and off that often in that type of temperature unless he has the thermostat set on 80 or something.
I would not be offended - if someone else noticed something that doesn't quite seem right, I would rather them mention it to me so I could possibly avert a problem. If nothing is wrong, then great. It could also be someone who recently purchased the unit - new to rv's and doesn't realize there is something wrong with the way it is operating.