I’m happy to pay to stay overnight somewhere but I don’t need any facilities other than water & waste probably twice a week. France, Spain, Italy, Germany and other countries have this pretty sorted. Anything from €5 to €15 per night and maybe €3 if you want to use the water & waste service point, although I did pay €28 per night for a great location in Cadiz. However that was very much an exception.
When I’m away I’ll do a mix of campsites, paid aires, and free spots depending on the location & services. It’s a great way to holiday & really explore an area. It’s not going to go away so why not try to come to a solution that works for the locals as well as the tourists. From previous comments it seems there’s a shortage of public toilets so you could tie them together somehow.
I’ve been to some aires in France that catered for probably 75 motorhomes, charging €8 per night plus €3 if you wanted water & waste. Everyone paid and everyone was spending locally. It wasn’t anything fancy, just a big gravel & grass area on the edge of Le Crotoy. Very busy in July & August bringing in approx €800 a day. That’d pay for itself pretty quickly even if you scaled it down loads.
I don’t think anyone is advocating for free facilities or to have their holiday subsidised. I think the real issue is that some people are ignoring rule number 1, as they do in all walks of life. Those people won’t care if you ban it; they’ll just keep doing it.