The point of the polices was to counter the incredibly destructive result of the surge of cocaine, crack, heroin use in the mid 1970s and early to mid 1980s. And the deaths from the drug use and the gangs fighting over the spoils. It really was a war. Mexico didn't seem to make it, I think the drugs won.
I know for some people these days it's cool to poo poo the so-called "war on drugs" but to Gen X who lived through the surge it was not a great time. Every day some news of deaths, fights, we were constantly reminded of it. Something had to be done and the free-for-all didn't seem to be working. I guess just like psychology you hear of examples where the stern family raises a wild child and the carefree family raises a straight-edge child the program backfired.
Drugs are chemicals just as is water and yes if a drug is useful then study it and use them for good if possible. But to others it seems many view all drugs as holy and that they can do no wrong is ridiculous.