We did the opposite as you are suggesting. We hauled a 150cc scooter on a receiver rack behind the motorhome for a couple of years. It was handy on certain occasions, but more often than not, it was either to cold, to hot(we don't like sweaty helmet heads)or raining.
We had a storage box on the back, but many times we wanted to buy more items than what the storage box would hold.
After 2 years we started towing a car. I can hook up the car quicker than I could load and secure the scooter and the comfort of a car is obvious.
We did like being able to park the scooter almost anywhere even in congested areas though.