It seems like te stupidest thing to me. Why are you going to attack someone who has politely asked you and/or your child to behave themselves or at least stop actively doing something harmful
Why the hell would they disincentivize their kids when someone has just given them an out to have a teachable moment and possibly nudge their kid behave better and possibly for the parent?
Crappy parents are probably aware that their kid is a bit shit and feel insecure about their parenting. Insecure people often lash out when given criticism while someone more confident would be able to learn rather than take it as a personal attack.