Theres another way to view that, we live in a tourist area in the west coast.
A motorhome often has, from my observation of 100's passing through our town, no more than two people on board.
Cars, people carriers or mini buses could have 5+ people and with no cook facilities in the vehicle would be much more likely to buy food, drinks and accommodation adding to the towns economy.
I have seen a number of discussions where folk want a carpark place overnight for as close to free as possible, so why would I think they'd not stock the van fridge and eat the van, maybe just go out for a drink in town ?
Our local supermarket carpark always had a good number of motorhomes, I wonder how many actually spend time buying things in town apart form fuel and food ?
I would be interested too see the data for where the moneys spent by motorhome owners if it exists ?
The issue of noise, waste etc from the minority and the visual impact of sheer numbers of large, often white motorhomes on the sea front or in one place is always going to upset some locals and businesses.
The views and interests of locals need to be satisfied with action from the local councillors who vote for them so why should be surprised !
Parking for motorhomes needs to carefully considered to avoid visual impact in my view.
We don't tend to stay in towns preferring the wild places or farm type campsites as we are fine off grid in our sliver micro camper, its more for economy rather than intended as stealth !
On the one weekend a year we do stay in a town, we buy our food at the festival all except breakfast.