I have sure known plenty of people who avoid or stopped using drugs, or associating with drug users, because of the laws.
That second remark is interesting, people can spot you as a drug user yet I don't get pushers giving me their business cards, your entire post sounds like the media figure who didn't believe that Nixon had been reelected in one of the biggest landslides in history, because she personally didn't know anyone who voted for him.
You probably mean that 1% of drug users who got caught and ended up getting randomly tested by the government while on probation. That's not a solution and otherwise nobody cares about the laws. Your chance of being caught is so astronomically low that no users take it into account.
“That second remark is interesting, people can spot you as a drug user yet I don't get pushers giving me their business cards”
It has nothing to do with outwardly displaying you are a user. If you dress wealthy and drive a flashy car to a hot night club, they will try to get friendly with you and give you a card. Most wealthy people who go to these clubs use drugs at least occasionally. These are the dealers for A-listers and celebrities.
The inherent harms of drugs were a minor or non-consideration? Really?