Why do restaurants allow children in after 7?

Cape May - Why do restaurants allow children in after 7? We were out to a nice place Saturday night, June 20 and three tables of parents let their kids run wild, almost knocking over waitresses while the parents drank and paid no attention to their kids. At a $150 night out for dinner, you should not have to deal with this. I know most parents are both working and daycare is raising their kids, but you really need to get them under control, or take them to a fast food place. You not only ruined my night, but everyone else's who was looking at you.