Drugs are fun. Many of the people who sell drugs are vicious, mean bastards; many of the people who sell drugs are friendly and enjoy making people happy.
Most people are capable of combining the consumption of drugs – whether alcohol, weed, pills or coke – with a happy and productive life. Some people are not. This suggests that they should probably avoid them, and that bad things will probably happen to them if they don’t avoid them.
The existence of the second group is not a sane argument for drug criminalisation, any more than the existence of appallingly bad drivers is a sane argument for car criminalisation.
Yes, some absurdly large percentage of the public want to keep the sale and use of drugs illegal. This merely proves that the public are ignorant and stupid, which we knew already.