I disagree.
Cool if you can use and not abuse, but you're in the minority. The laws aren't in place just to stop people from having fun, though, they're for the safety of those around you.

You did say use, and I think that is key. If you're living in your own house, the police will not respond to a call if someone reports you for smoking meth. It's illegal, but using drugs in the privacy of your own home isn't something that's enforced. If they're called for another reason and find some crack you'll get booked for it, because the implication is that drug abuse is a causal factor in your breaking of other laws.

We're footing the bill for millions of hospital visits from drug overdoses, and countless acts of theft/violence that follow drug usage.

The drugs that people use are super fun, I'm sure, but they often come at the cost of outrageous violence throughout the supply chain that include mass beheadings/executions and people being skinned alive.

The drug trade is tangentially the greatest source of murder in the United States and absolutely is throughout Mexico and many of the countries in Central and South America.

Also people think the Taliban is pretty bad, and their arms are funded through the drug trade. Before ISIS took control of Iraqi oil fields and historic sites, they were funded primarily on drug trafficking as well.

I'm not a drug user, obviously, but for the record I'm not opposed to the legalization of weed. I do, however, think that a lot of smokers are super annoying.

Source: I worked for the DoD in an intelligence role, and at times worked with law enforcement specifically related to substance abuse.