It happens a lot, especially in Europe. Europeans don't seem to go camping to enjoy nature, but for a holiday and partying. And a lot of their campgrounds have beer gardens. Not so much the case in in North America.
I have not had much success in asking people to be quieter. Like your experience, they only comply for a short time. On a tour this summer we had a couple of young guys who closed down the beer garden. One of them was heaving up the night's refreshments most of the night. Sometimes there is a little justice
What we learned is to pay a little extra and get out of the cheaper tenting section if possible. We also do not camp close to any groups of young people. We have also just picked up our gear and moved to another spot, and at times to a quieter place that was not actually a designated camping spot.
I think it is just part of the touring experience.