There's also the risk of an insurance claim. If the property owner has a dock (or deck platform) and someone gets hurt, the property owners probably don't want to deal with the possibility of being sued.
And of course the trash that gets left behind. Take a ride down Edgemere along both ponds after a sunny day during the perch run. After 50+ vehicles have been parked there. It's easy to find empty bait containers, crushed beer cans, cigarette butts, plastic bags, food wrappers, and tangled lines all along the shore.
I probably wouldn't want to deal with that either.