I share your opinion on the effects and dangers of drugs, but these are personal choices.

There is no common sense or consistency in having alcohol legal and marijuana illegal. Most hard-line conservatives in favor of rigid anti-drug laws rarely have a coherent answer for that. Every danger and negative effect you correctly list as related to drugs is also applicable to alcohol.

Either

A: Admit that society can handle pot at least as well as it handles beer and tequila, and decriminalize it, or

B: Admit that the negative effects on society from alcohol are far worse than those from marijuana, and restore Prohibition.

No other alternative makes sense. For the record, I vote for "A."