Because on the metalevel it's important for people to understand that these issues can be solved efficiently with informed debate, rather than with screeching and shouting and "think of the children" and knockless raids.

People need to know that results-focused thinking is important in the first place.

Maybe you are overestimating how many people make this effort. For the most part, when you say "solved" most people will take that to mean "my side won" and when your side is for the criminalization of drugs a priori then if screeching and shouting and thinking about kids are what is necessary to get the job done, then that's what will happen. Most people don't do this on purpose, rather the thought never occurs to them to examine why they support a thing, i.e. what their goals are, and whether the measures they endorse to further these alleged goals actually do anything to accomplish them.

Why do people support criminalization of drugs? Do they just think that drugs are really bad and that people shouldn't use them no matter what? Putting aside for a moment whether this belief is justified, does the current regime even manage to reduce drug use? Maybe they just think that drug users are bad people and need to be punished, but I wonder what such people think of enriching drug cartels, which the policies they support tend to do. Then there is the harm reduction cohort, which is the one that I think has finally come around to the fact that criminalization isn't accomplishing that goal, and is why we are starting to see legalization after the destruction of millions of lives.

I wonder, how long after repeal of Prohibition in the United States did it take before everyone agreed it was a bad idea?

Some, of course had turned their coats already at the time of repeal. ( http://en.wikipedia.org/wiki/Prohibition_in_the_United_State... )

Today, 82 years after the repeal, there are ca. 'dry' counties in the US. In some cases I can understand the intention (a remote village in Alaska for instance, where the villagers would drink themselves to death because there's nothing else to do). In most cases however it's just shortsighted backwardness. Studies have shown that dry counties have a significantly higher rate of alcohol related traffic deaths than wet counties. The most likely explanation is not that people in dry counties drink more, but that they have to travel a larger distance for their alcohol, thus increasing the chance of a DUI accident.

> Studies have shown that dry counties have a significantly higher rate of alcohol related traffic deaths than wet counties.

Yes, but correlation does not imply causation, which might be the other way round: counties have decided to be dry because they have recognized they have alcohol problems.

(You can have the same debate about gun control, etc.)

But the causation may also be that being "dry" actually incites people to use alcohol. I'm in the North of Europe, a country where availability of alcohol is restricted (strong liquor only in state monopoly stores, beer sold only at specific hours and not to minors and not to those already under influence), and the drinking culture is traditionally binge-drinking. People take ferry trips to buy loads of cheap alcohol from the neighbours. They buy enough to last two months, and then they drink it in two weeks.

There was a dry town in Oregon a while back:

http://en.wikipedia.org/wiki/Monmouth,_Oregon

My recollection is that there were accidents outside of town because students would drive somewhere else to drink and then drive back.