Last year when I was with the Other Entourage, the French did try to charge us extra per tent, rather than per car; we talked them out of it, but it's not actually a bad idea. Maybe they could charge a flat rate for one vehicle and up to a certain number (4?) of people, and then a supplement for more people/tents?
My own concern was the fact that they were letting people in (either de facto or de jure) well before they were prepared to open the sanitary facilities, and with something like 500 people on the site by Monday afternoon, it's no wonder there was an epidemic of intestinal nature -- and I would not be surprised if eventually they have an outbreak of cholera if they keep it up. I realize that this may be their obstinate refusal to give in to the people who arrive earlier than the ACO want them there, but if they are not going to turf the early people out -- and in fact if they are letting people in on Monday -- then common sense would require that the sanitary facilities be available when the number of people on site reaches critical mass. I don't know what the law is in France, but in most countries a place that invites an international epidemic would be cited by the Health Department at the least!
I would hate to see them wait to have to cope with a tragedy before they do anything constructive -- but with the number of people crowding in every year, both the current unrestricted fireworks policy and the lack of proper sanitation are tragedies in waiting. What will happen when one of those flares lands on a tent that is in the middle of a compound where many of the people are too drunk to know their campsite is afire?
I do think everyone does his or her best to keep things nice for everyone, but attention must be paid in a village that size, to common sense safety measures, I think.