Hollywood "Values"

It seems like every other day there is some star that winds up dead, drugged out, divorced after a couple of weeks, etc. I just don't understand it. Besides the entertainment value that most of those in Hollywood provide, how can any of us take them seriously outside of the big screen? I know that there are exceptions to the rule of conduct that I just outlined. Can someone explain to me why the rules just don't apply to those in Hollywood? Why do we as parents allow our children to let so many of these people be role models?