I think it just depends on the park. I couldn't live without our dog parks. The one I go to has a $40 yearly fee (it's a state park) or a $6 one-time entry fee. It's also monitored by the park rangers, who drive by alot and respond to calls, etc (you can call a park ranger if a dog is out of control, and they will come and access the situation). I've never had any issues here. Sure, you get a little scrabble every now and then, they're dogs, it's going to happen. And you get the weirdos (people, I mean! LOL) that come out sometimes, but all in all, I LOVE our dog park.
Then again, I go to another dog park that I've never had any issues with either. And it's completely free and not monitored. It's definitely more relaxed and rule-free, which is kind of nice sometimes. I got yelled at at the other park for giving Jackson a treat when he came when called
A person came and yelled at me and said I'm not allowed to bring treats... haha! Sooo... I love both of ours and pick and choose which one I'm in the mood for.