I think your major premise is wrong here. I don't think marijuana causes people to act like potheads. I think potheads are one group of people who use marijuana just because they are potheads. When marijuana was made illegal and the penalties for use increased, the casual user was scared off. Now marijuana sold on the streets is much more concentrated in THC than what it was decades ago. This is because the primary customer, the potheads, want the extreme effects. The same is true for all illegal drugs. Cocaine sold at the turn of the 20th century is nothing in concentration like cocaine sold to people today.
You’ve been reading those DEA handouts again...
You’ve got some flawed logic, there, burzum.
The quality of drugs doesn’t go up because they are illegal. The strongest pot in the world can be had in Amsterdam, and made it’s first appearance in that city.
In the culture of the modern world, there’s a constant push for all consumer products to become more competitive with each other. With or without drug laws, pot will continue get more potent.
As for the word “pothead”. To me it doesn’t designate a segment of culture as much as it does a level of addiction. A pothead is psychologically addicted to pot. I know some potheads. They scream their heads off when I tell them they are addicted, and then they light up another joint. The ones I know are not members of any identifiable subculture. They are simply people who smoke too much pot.