The dude was being a full-on Karen in that instance, and, in any other context, he would have been mocked. He was concerned because letting dogs running loose hurts his ability to bird watch... in Manhattan, the largest and most dense city in the country. Like, it's cool that there are actually birds and other critters in Central Park, it shows how resilient nature is, but, if you're a serious birder, you're in the wrong fucking place. If dogs weren't tearing up bird habitat, it would be vagrants instead.