Somehow the vast majority of people who take legal hard drugs such as vicodin or dilaudid, don't overdose on them. There's a culture built around taking these drugs responsibly according to their directions. We have that very strongly ingrained in our culture about alcohol. I think that same culture would develop if your cocaine came in a box from CVS with proper instructions on when you can take it and what side effects to look for.
Of course people are going to make mistakes. They are going to abuse drugs. But that is happening today. Trying to solve that by keeping the drugs away sounds like the same policies in the war on drugs that we are saying aren't working and leading to legalization