Who is the target market here? The members would all be people who own property near popular vacation sites, which presumably well-off people with disposable income. But those people are not looking to travel and then stay in their cars in a stranger's driveway. They can afford hotels and vacation house rentals.
This seems like the worst of both worlds. People who don't care about the price can afford better accommodations. People trying to travel on a budget won't have properties worth using as a host and can't even participate.
I would guess this maybe targets people wealthy enough to own both property near a popular vacation site and an RV, but who want to travel to other popular vacation sites that don't have nearby RV hookups.
It would arguably make sense as an AirBNB for driveways, as in let the hosts and the travelers be different people with very different demographics, but requiring all users to be both doesn't make any sense.