Public is just that. Sharing it is another story. I've always been happy to share hunting/fishing spots because I want others to share in succeeding like I do. I've had them stand right next to me, use the same rig, and I will still outfish them!! So I figure . . . what's the harm?
Actually, One of my favorite spots used to be Pickaroon. 25 years ago you could be one of maybe two camps there on a holidday like Labor Day. Now, you can walk accross the whole site jumping from 5er to 5er! The fishing has suffered. People don't follow the rules. I caught some guys using live bait there once, and they kept on going even after I "educated" them. They soon left after I started writing down their vehicle description and license plate! Respect for all outdoors is often ignored, so we seek out more and more remote areas and keep them closer to the vest.
Personally, I blame better roads for easier access to the BMW" and "Cadilac" outdoorsmen.