That's not what I was saying at all. Obviously there are aggressive animals or animals who don't do well with other animals. It's how you control them that makes you competent.

What I'm saying is - If someone has an aggressive dog and they let it roam free, run around a beach loose (like the dimwit I ran into) or anything of the sort - then yes they're stupid or incompetent.

You might want to be careful letting your dog greet other dogs.. Leashes or no leashes.
1. You don't know if that other dog has fleas, kennel cough, worms or anything else that is catchy. Dogs like to nose sniff and butt sniff - great way to pass worm eggs since worms leave eggs around the butt* and top of the tail that hangs over their butt. The cute dogs saying "hi" to each other could cost you a vet bill in a few days.
2. You don't know how the OTHER dog is going to react. Just because yours is friendly doesn't mean the other is.