Many criminologists have come to the conclusion that, while it is true most hard drug users smoked weed, this does not entail a correlation. Most hard drug users also smoked cigarettes, drank beer, drank milk, ate macaroni and cheese, watched television, etc. at some point in their lives. Most hard drug users would have been willing to take any and every drug- could you imagine someone saying "I shoot heroin, but no way would I ever mess with weed"? It's like saying most major leaguers used to play tee-ball, but tee-ball is by no means some large gateway into the major leagues.