Everyone knows the "gateway drug" thing is bullshit. You don't smoke weed for a couple weeks and then gradually begin to experiment with progressively more dangerous and potent substances until you end up ODing in a Burger King bathroom.
It's just not true.
I will say however that the black market we're forced to resort to in order to buy a naturally occurring flower — a completely harmless one, at that — is the main reason our country is addicted to speed and opiates.
I mean let's not forget that there's no necessary "processing" involved in making marijuana consumable. You plant it, it grows, you grind up the buds, ignite, inhale and exhale. There's no ether or pseudoephedrine involved and it's not going to explode and burn your trailer down.
Racism and prohibition turned a miraculous all-natural wonder drug into something so mysterious and frowned upon that millions of people all around the world have no other choice but to go to the same places where every other illicit substance might be found, just to get a few buds clipped from a cannabis plant.
If the shit was legal everywhere, non-criminals who find cannabinoids to be beneficial could go to a safe, regulated place to buy their herbs or even grow their own garden — like any other fruit or vegetable — rather than hitting up a drug dealer and risking your freedom.
On a different note than that though, people with addictive personalities have a hard time turning down something that feels amazing, regardless of how dangerous it may or may not be. So if the dope man gets in some other shit, they'll probably be inclined to buy it. When that acid on paper turns out to be pcp or some random research chemical though, shit's not real fun anymore. Or maybe you're just some teenager buying dabs from a solid plug who gets perc 10's and 30's a couple times a month. You see the dude railing one every couple hours and he seems perfectly fine so next time he offers it up, you try it. Turns out it feels pretty good. So good that you feel like dropping half your paycheck on them every week. So there's one more thing the gateway of black market botanicals leads to.
Marijuana prohibition is the real gateway drug, is what I'm getting at. That's how I see it, anyhow.