I am not willing to pay for unlimited drugs and healthcares for users, which would happen if those substances were made legal tomorrow.
And you aren't already?
Anyone who wants to do drugs are doing so right now. Whether or not they are legal doesn't matter.
The prohibition artificially inflates the value, and creates a black market for the substances. If legalized and regulated, prices would fall by a substantial amount, and the cost and violence that comes with the drug war would vanish. I'd wager that it would cost FAR less to treat addicts than it's costing us to continue this worthless drug war we are in.
Who do you think is paying for it now?
Simply allowing the home growing of pot in the USA would well and truly yank the rug out from under Zeta. Pot is far from an utterly benign thing, but the prognosis for a heavy pot user who quits is better than the same for alcohol or tobacco.