A GM and an unfortunate parent moment

A few days ago, I was at the park with some friends and their children. One of the wooden platforms on the playground equipment was reachable from one side by a webbing of rope which was fairly difficult to climb. The platform was about 5 feet off the ground. My friend's little girl was attempting to climb up, but was having trouble. There was a set of steps on the far side which made it much easier to reach the platform, but of course, it wasn't about getting up there, it was about getting up there via the rope webbing. I offered to help her up by going up there myself and then pulling her up. I went around and walked up the steps and by the time I had got over to where she was, there was another little girl standing in front of her trying to get up as well. She was struggling, so I offered to help her. She thanked me with a smile and went down the steps on the other side. As soon as she rounded the corner, I heard her say "Mommy, That man helped me!" I immediately prepared myself for confrontation, as people in this area do not appreciate any strangers touching their children. I went ahead and lifted my friends daughter up as well. Just as I got her up on the platform, a small boy, approx 2 years old, came running up the steps. He immediately decided he was going to climb down via the rope webbing. I foresaw disaster and instinctively grabbed him so he would not fall. I went ahead and helped him climb down as this was his goal. As I was doing that, his mother comes up the steps and sees what is going on. I tell her that he would have likely fallen if he would have attempted to climb down on his own, and she just glared at me. It turns out that the little boy was the brother of the first girl I had helped up so she was already suspicious of me. The mother never said anything to me, and I avoided any further contact with her children for the rest of the time I was there. Anyway, my point to all of this is: How sad is the state of society when you are resented for averting injury to a child?