This is not the first time I’ve seen aggressive behavior by parents who think their child should be “first” or “best”. I learned a long tine ago to avoid these events.
As for the attitude, well why but just to go Walmart if your child didn’t get any eggs misses the entire point of the hunt. It’s the joy of participation, and of discovering and picking up the egg on your own, not necessarily to get a chocolate.
The best hunt I’ve seen was for a spring birthday party. The very smart parents had the children pick colors out of a jar. When each child had a color, they told the kids to find the eggs matching that color. Every color matched six plastic eggs. Once a child found all six eggs, she or he could help a friend, if asked, to search. It turned a competitive event into a cooperative activity. I think kids got prizes by order of finishing (so it was a little competitive but not insane). Ages ranged from four to ten.