Don't know about motor homes, but my diesel 3500 duly pick-up truck ... well?? If I stomp on the "gas" peddle, the rear tires spin and if on gravel will throw gravel half a mile! When driving, if I stomp on the "peddle", it lunges like a jack rabbit. When towing, if I do jack-rabbit starts, I can get a pretty good edge on a lot of smaller cars.
I'm on my second diesel duly. I remember I was really shocked how much of a jack-rabbit kick-off my first one had, when I did that the first time. It whipped the socks off any gasoline auto I think I ever had.
Now ... a motor home can have 20-30 thousand pounds of weight the engine has to over come inertia. Even 18 wheelers, when driving just the tractor and no trailer, have phenomenal pick-up. Add the trailer loaded, and they lumber to get up speed.
Depending upon the size of engine and the weight of the motorhome, could account for a much slower "Jack rabbit" experience.