Dog Wars- an editorial

I am worried about our small dog world. Today, I overheard a confrontation involving a friend of mine. It was over one of the sensitive issues, oversized dogs. Apparently this gentleman was reprimanded because he had a puppy lab that appeared to be over the weight limit. I am quite sure that it was, but he also had a smaller mature dog that hardly moves, threatens no one and is uncomfortable in the larger dog park. The puppy lab is exuberant but I have never seen it threaten or harm any other dog. The gentleman left as I was entering, so I do not know his feelings, but I can imagine.
Now, rules are rules, right? Well in out little dog world, apparently not. A few minutes after that gentleman left, a lady arrived with two dogs one that had to be at least 50-60 lbs. No one complained, no snide comments issued. The difference? The lady is well known in our park, the dog is old and moves slowly. The owner of the dog in the offensive case was male, the owner of the dog in the ok case was female.
If we look beyond this, by a strict weight test, we have several small in stature, but shall we say rotund dogs that surely over the limit- but no complaints.
Yes, we have rules, but can't common sense apply? I hope this generates much discussion. And while we are at it, how about those other "offenses". My particular favorite is the seemingly increasing number of people that visit the park to socialize and completely ignore the piles of poop their precious pooches are generating. Then there is my other pet peeve- humping. I realize that most of the male dogs are neutered, but several dogs exhibit this behavior which can be both sexual and dominance related. I have heard laughter among some when they see this, but in many cases I consider this unacceptable aggressive behavior- often ignored by the owners. I have never seen a dog and owner asked to leave due to pooping or humping. Maybe it is about time. Just a thought.