Hello @bugsymagoo3290
Camping and outdoor recreation can be great places to be social with others and explore. In your example though you are clearly nominating a Youth Camp Site. As you explain these are primarily targeted to religious groups and Boy/Girl Scouts planned trips. These tend to focus on kids under 18 years of age with a number of adult chaperones. While a few parents will be there, the bulk of the children will be there with adults that are not their parent or legal guardian. So Niantic considers this under their K-12 rejection rationale.
Please see the Criteria Clarification here: Private Residences, Farmland & K-12