I've been thinking this way for several months at least; here's the post which prompted me to discuss it here.
I think smoking pot is stupid. Then again, I think getting drunk is stupid, too. Generally I'm not interested in intoxicants; I'll have a beer or a margerita or something once in a while, but just one and not to excess. I like margerita "wine coolers" better, in fact, because there's so much less alcohol in them than the real thing, and they taste about the same.
I have no sympathy for people who live only to get drunk/high, either. I think it's stupid to work all week solely so you have enough money to "party" on the weekend. Spending money on enough intoxicants to keep you blitzed for forty-eight hours is stupid.
But being stupid isn't illegal. If it were, at least half the country would be in jail.
The points made in the linked post are mostly correct. But all else being equal, if you legalize pot, some big corporations will get involved in selling it...and the price per unit will drop. Sure, the now-legal growers would benefit in the short term; but in the long term, they'd be out-competed by big corporations, which would be able to beat them on quality, quantity, and price-per-unit. The criminal factor would drop out of the industry pretty quickly in the face of government regulation, which is inevitable. Legal pot would fall either under the sway of the FDA or the BATFE (BATFEM? Adding "marajuana" to the list should spur a reorg of the acronym. I nominate "BFMEAT", the Bureau of Firearms, Marajuana, Explosives, Alcohol, and Tobacco. They're a bunch of dicks over there anyway).
The criminal factor would drop out one of two ways: #1 they'd voluntarily leave the industry because they don't like complying with the regulations. #2 they would be arrested and jailed for violating the regulations because they are, after all, criminals--they're ignoring the illgality of pot now; why would they change?--and it's a lot harder to run a pot-growing business when you're in jail.
Certainly the easy profits would be gone. As it stands now, anyone can grow and sell marajuana if he wants to risk jail; and there are no regulations regarding purity, labeling, or anything of the sort. If he has help growing and tending the pot, he can pay his workers whatever he can negotiate ("I'll give you an ounce if you water the plants this weekend while I'm down in Vegas").
Legalize it, and all that changes: workers must be paid minimum wage and there has to be withholding and SSI and FICA and all kinds of paperwork. The work site is subject to OSHA and EPA regulations. Sale of the stuff is regulated by FDA or BFMEAT. Agriculture regluations apply. Interstate commerce regulations apply. Taxes must be paid. Etcetera, etcetera, etcetera, ad nauseum.
After a decade or two, the (formerly) illegal growers are out of business and RJ Reynolds et al are making money hand over fist in their new side line. The government is raking in the tax revenue.
I don't really think legalized marajuana will have much effect on international drug trade, though. My impression is that most of the marajuana consumed in the US is domestic; the stuff is too bulky to smuggle easily, where other drugs are more compact and face less competition from domestic suppliers. (Cocaine, for example, comes from plants we don't grow here.)
I don't think legalizing all drugs is a good idea. I do think that securing our borders is essential and that a serious go at border security would stop a lot of the stuff coming into the US from Mexico. And I think that if we stopped bothering with marajuana it would free up a lot of resources to deal with those who trade in the harder drugs.
So let the potheads have their weed...and then bury them in paperwork and taxation. It's all they deserve, anyway.