I think the average person (including myself) is just skeptical this is a problem worth having. A rube goldberg where everything has to go right.
It seems like the best case scenario is "We legalize drugs and then raise tax dollars and then use that money to fund programs so that people that are addicted aren't harmed too much in the long run" just seems not ideal.
I get the arguments for personal liberty, but we wouldn't allow other risky behavior that has a such huge societal cost.