I've addressed this in my blog on the tragedy of the commons: https://steemit.com/economics/@joshbowens/the-tragedy-of-the-commons-reubtted

People already know that this type of behavior is dangerous and the actions against people who commit these acts are a waste of tax money, but the fact that people continue to do it and in this instance put their children in danger in the process, gives people a reason to support measures taken by the state to counteract drug use.