Addicted to Heroin: How Can the “smart” People Be Brainwashed to Think Marijuana Is Horrible?

Question by Abayomi: How can the “smart” people be brainwashed to think Marijuana is horrible?
Every article I read involving marijuana I always stumble upon the smart persons answer like,
“Don’t ever try marijuana. It will ruin your life. You’ll become addicted and be at risk of it even after the first time! IT’S BAD! You’ll be sure do other horrible drugs like methamphetamine and heroin.”
Where’s the fact of this? I’ve never seen a marijuana smoker do vulgar things for his “fix”.
I’ve never seen anyone become retarded. I’ve definatly never seen laced marijuana in my life. If you believe that the horrible, shady “drug” dealers out there really grind up a half a gram of meth, $ 70 to $ 100 a gram, to add to a bag of weed that they charge you thrity dollars for, you must be out of your mind. They’re looking to earn profit. Not lose it all to get you addicted to a drug that you’ll probably most definatly quit when you figure out it’s something you didn’t want to do.
Last but not least, someone is probably thinking about commenting the brainwashing statement in my question because I’m “a stupid stoner that thinks the government brainwashes people”. I’m not even going to get started with how possible and true that is. You’re the perfect example.