Having a nice day in the dog park is more than just opening the gate.
Many people think that taking a dog out, is a great thing they are doing - but great would be twice a day for the dogs entire life. They would also encourage their dog to learn to understand what dogs to approach and what not to. Knowing this implicitly because of their vast experience with random dogs in dog parks. What to do when another dominating dog comes over that they don't want to engage with, but they dont want to encourage a bite either (ie getting your dog to the social state that they dont go automatically into fight or flight mode).
The day in the park should be fun for dog and owner, but its that kind of boring fun, you know, responsible fun. The fine line is not micro managing dogs, which many overly anxious owners do, but also not being engrossed with your phone or being distracted and not watching your dog. THIS is your dog's time, so I always make sure that they are getting fully out of it what they can. Not forcing it, but looking at ways to remove obstacles to them developing and having an enriched experience.
Or is this just me?