[Know your rights]

if the criterion for "X should be criminalized" is "X has societal 'net negatives'" then that's true whether X is marijuana or alcohol (or eating unhealthily or getting too little sleep).

Wrong!

Marijuana IS criminalized. No change required.
Alcohol is NOT criminalized. No change required.

Now you're changing your argument, to "laws should remain as is." I guess that also applies to nearly-unrestricted abortion, and still-too-high tax rates?

[G Larry]

No, I am straightening out your "should" vs. real world "is".

Societies "net negatives" will only be resolved in heaven.
That is no reason to choose to add to them.