Personal responsibility is an excuse for lazy regulation. These things are designed to be harmful, for the express purpose of squeezing money out of people, as efficiently as possible. We know that some people are psychologically and genetically more prone to addiction than others, and that people like that will be extremely likely to form addictions with gambling or drugs when we make those things easy to access.

What would you rather have? More regulated gambling and less addicts, or unregulated gambling and more addicts? Personally, I prefer the former.