Supply and demand. Nobody said it was yashrus though.
This isn’t limited to camps though. I recently overheard several seminary age girls on the “F” train heading to a job interview at a “heimishe” business for a basic 9-5 office secretary type job(I wont reveal the business name for obvious reasons). They were discussing What they would answer if asked what their salary expectations were. One girl said she would ask for $250 a week and another replied, dont, she knows another girl who asked for that earlier in the week on her interview and was told that they were not looking to pay that much.
Back to camps for a second. When counselors were employees and paid by the camp, they took their responsibility to ensure a good time for their campers a lot greater. Now, while as a whole they are a group of good boys and girls, since they have to pay to be in camp, or dont get paid for doing their job, they seek to maximize their own fun as well, sometimes to the detriment of the campers.