Diogenes wrote: One does not need to be an engineer to realize that someone chopping at the bridge timbers is liable to damage the bridge. The prevention of damage is not engineering, it's maintenance.
Think of a house on stilts. Think of there being a LOT of stilts (say, Florida panhandle, near the beach, designed to weather a severe storm) supporting the house.
Someone comes along, looks at the forest of stilts and goes "There's too many here, and I think a lot of them are unnecessary. I'm going to remove one - there shouldn't be any problem with removing just one." And does so... and nothing happens. So a few more people come along, a fe more stilts are removed, and then a few more - to the point where the people removing stilts finally go "You know, I think that's probably enough." Even with significantly fewer, the house is still sturdy enough for normal conditions.
So far, so good.
What happens when the next hurricane hits? The safety margins have been seriously eroded - but the house may survive... or it may not.
I have seen a lot of sociological 'stilts' pulled out the last 30 years or so. There was the 'war on poverty', which has seemed to entrench a class permanently in that state. The concept of a good education being important has largely been dumped in some cultures for a chase of bling and basketball, and mysogynistic behavior.
Families are considered by some to be superflous, language and attitudes are common now that would have been pretty much unacceptable 30 years back. We see self-destructive social behavior lauded and never seem to wonder - "Okay, just how MUCH of this is tolerable before another pillar gets destroyed?"
We see politicians morph from public servants to an elected, untouchable elite. There are no public 'heroes' any more, no mainstream ideal of an honorable man or woman. As fast as one seems to appear, the media tears them down if they're of the incorrect political persuasion, or hides their follies and foibles if they're properly aligned.
Legalization of drugs may have been possible 40 years back for a time. But now? There's few pillars left, and the house is getting shakey. Is drug prohibition one of them?
What would happen (seriously) if it were removed? What unanticipated consequences could arise? The hopeful think everything will somehow get better. The pessimistic think that deaths will rise, and society will be affected.
I think what we have now doesn't work well. And changing it by removing the current drug prohibition (and possibly introducing severe DUI laws) isn't going to provide a better end state and could possibly make things worse.
I could well be wrong on that - the repeal of Prohibition certainly didn't result in a catastrophe, and over the decades since that event a lot of the cutural permissions towards drinking have been rescinded. But there were a LOT of deaths due to alcohol consumption in those decades, both directly and indirectly.
Are we ready to accept such deaths again, knowing that 50, 60 years down the road it won't be culturally acceptable to drug & drive? Introduce Darwinian selection and culling to the population on a vast scale, weeding out those who can't handle their dope... usually through their death by accident or OD?
That really seems the more likely result to me. Make it available, make it cheap - and the deaths will rise.
When opinion and reality conflict - guess which one is going to win in the long run.