Driving while under the influence creates a condition where one can cause harm with no further intent. General being under the influence does not, to the limit of philosophical zombies.

Furthermore, any drug user's increased propensity towards $whatever is going to correspond to the dosage they've taken. Criminalization of the substance itself is still not implied, just as driving with a trunk full of beer is fine. And there still exists the correlated crime-by-association [0] of public intoxication.

[0] Observe how the legal cancer spreads based not on true misdeeds, but on ancillary behaviors that are simply correlated to misdeeds. But if correlation were sufficient justification, then profiling based on skin color and lack of political connection would also be perfectly acceptable! Since the entire point of the rule of law is to protect the long tail of individual outliers, creating avenues to arbitrarily persecute people by association is its destruction.