You realize rabies is contagious and can be passed to humans right? You think people want to bring their kids in to that? That's why any dog park worth a darn actually enforces the shots requirement. You sound close minded.
If you wanted to leave your dog in the car and check out the park yourself I'm sure she would have no problem letting you in. You should be happy the park has people who enforce the rules. I'd rather a park be too strict then have a bunch of people who could care less.