What is the reason for only 2 weeks rv camping when I was a kid my grandparent stayed all summer best times of my life

A couple of reasons changed at all state parks. One so others have a chance at the good sites. Another reason was people living at the lake and something about squatter rights.

Federal regulations state that civilians are permitted to occupy the national forest in one place for a maximum of fourteen days, after which you are required to move, if i remember correctly, a minimum of fifty feet for at least twenty four hours. This applies to all national forest, and the BLM lands. I guess it applies to the national park campgrounds too, unless you're a campground host.

Most RV locations have a two-week maximum stay period during the peak season. This is usually done to allow more visitors into the park at prime locations. These restrictions are often removed during the off-peak season.

We stayed a month while moving but had to move and change parks after a month. I'm not sure why though.