Nicotine and alcohol are to mainstream to make illegal, they have been around for so long and are part of culture. Let's say someone would discover the substance alcohol today and we don't have a history with it than they would probably make it illegal because of it's addictive and harmful effects.
Marijuana is also illegal because of some other reasons.
- It's associated with oppressed ethnic groups. Marijuana wasn't popular among white people before the 1960's. So you could argue that it's illegal out of racists believes.
- It's addictive. (There's no doubt about that but the question is how addictive is it really and how should we deal with it? )
- Has been historically linked with other illegal drugs. Marijuana and cocaine are the 2 most popular drugs and sometimes people combine them or use different type of drugs. That doesn't give it a good reputation.
- Governments wrongly thought that by making a war on drugs they can make people quit so in their mind it was a good thing to make it illegal. The thing is in reality it's costing a lot of tax payers money that's wasted. Users are being forced to go into a criminal circuit and pay a higher price than you would in a free market. Out of an economic perspective it would be smarter to tax marijuana sales so it brings in revenue for the government instead of costing us money.
- Not much research has been done what the medicinal use cases are. Some users with different types of illness claim to receive benefits from marijuana use. But there are not much scientific studies making the same conclusions since there hasn't been done a lot of research. It's hard to do research when it's illegal because they need special approvement from the government.
