It's not always easy to find out why we get banned but, on several occasions, it has been because of the private business interests of powerful councillors. Sometimes it has been because of complaints from business interests in the leisure industry. I can give examples of both. This is where the loudest voices are.
It is never in response to public demand. (Edit - only one that I can think of - a beach car park in Cornwall)
Remember too, that it is not an either/or situation ever. These bans on motorhomes come from councils who, otherwise, bleat about decreasing social care; closing libraries and saving money. These bans cost money and councils seem to find it easy to find the money for them.