Many americans don't seem to understand this because they've grown up in the US media bubble and were educated in US schools which don't tend to really accurately portray the rest of the world.
Going out and living in other countries you find how impressively different things can be.
For instance, an acquaintance of mine who is a medical doctor who treats terminally ill patients, had his life ruined (and is in jail now) because the DEA decided he was writing too many prescriptions. Those same drugs- that he determined were medically necessary and he's a DOCTOR, can be bought over the counter in Chile, and many other countries south of the US border. Walking around chile you don't see a lot of stoners or drug addicts (in fact, I haven't seen any homeless at all) compared to the USA.
Nevermind that the person who decided he was writing "too many" of these prescriptions has no medical training and was doing so based on what amounts to a quota system whereby over time patients are increasingly denied the drugs they need as their doctors become afraid of the same fate that befell my acquaintance. This fear causes fewer prescriptions to be written over all, lowering the standard for "too many", causing those who didn't deny their patients the drugs they need to be prosecuted, installing more few, further lowering the numbers, etc. It is a self reinforcing cycle.
So, please tell me why a doctor had his life ruined for giving his patients- terminally ill, remember- prescriptions for drugs that you can buy over the counter in many countries? Please tell me why the USA is pursuing a program that ensures that ill people are in agony?
It is because the USA has gone off the deep end in certain areas.
Yet attempting to defend this doctor to others who also went to high school with him, mostly got no sympathy. To those americans' eyes he was a "Drug dealer" and a "scourge on society."