We haven't become a culture of stoners. It's like lumping all people who drink wine as bunch of alcoholics. At a quick glance you could say "everybody drinks alcohol", but are we a "culture of alcoholics"? Kudos to you for having an open and minimally judgemental discussion with your son. He'll only benefit by allowing him to think for himself while making sense of the world. In the end he'll be smarter for it.