If alcohol is so bad, why aren't you out trying to ban it? If marijuana is only as bad as alcohol, why is it motivating you... and alcohol doesn't?
What seperates marijuana from alcohol to the extent that you need it banned?
I don't drink. I stopped nearly 30 years ago and just never started again. As is obvious from even one episode of "Moonshiners", banning alcohol will not be enough to do away with it, people have been making their particular brew for as long as there have been people. It has been tried, and the effect was to entrench criminal enterprises which provided the product.
While there are criminal enterprises which provide illegal drugs, including Marijuana, they do not enjoy the more universal acceptance those alcohol producing enterprises did because the use of the product is not as wide as the use of alcohol is. Letting those enterprises go 'legit' will not change the nature of their other dealings, it will only fund and front for them.
The damage evident to anyone who has dealt with people who consume alcohol in excess is obvious, at least to most of us. But alcohol isn't always consumed to the level that there is a noticeable high. A drink (one) in a social setting may be consumed without noticeable effect except to relax the person consuming it. Continue, and the effects become more profound.
Over the years, I have known many people who smoke weed, too. One thing is must note is that while some ethanol consumers are out of control, most I know will limit the amount they consume to avoid a buzz, especially if they are driving. With weed, the objective is to get a buzz, period. I can't say I have known anyone who didn't smoke for the high. Not a little puff off a joint to relax, but enough to cop a buzz.
That is a seminal difference in the two drugs, imho.
With ethanol it is possible to anticipate levels of intoxication and not overdo it. Levels of alcohol in drinks are predictable and regulated by law, or clearly marked. Levels of intoxication are predictable, too, especially for the user who has been consuming for a little while, but even quantifiable, with predictable results for all but the most heavy users.
With weed, not so much. Not only are dosages not predictable, I can't ever recall someone saying "Two's my limit, I gotta drive.".
Admittedly, there is a Catch-22 there which prevents the study of levels of intoxicant and effects, the ability to test those levels and establish guidelines which would keep impaired drivers off the road and from performing critical functions with marijuana, and part of that difficulty stems from variations in strength of different plants, parts of plants, and even varieties of the plant, which render such quantification difficult for both the user and the persons charged with enforcing laws which exist to encourage people to not drive under the undue influence of the drug.
Individual variations in physiology may have an effect, and for that matter, overall usage, much as with alcohol, may mask the people who have higher intoxicant levels yet remain 'functional'. Much as with hardcore drinkers, there is an optimal level of intoxication with which they function best, compared to the absence of the intoxicant which leads to adverse effects. People of this nature only complicate efforts to find a reasonable level.
At present, the only way to regulate Marijuana and driving is to either commit the using populace to suffer the subjective opinions of LEOs as witnesses to the apparent mental state and ability of a person to drive, or allow unfettered usage of Marijuana among drivers, or to ban the use entirely, especially on the road.
That single difficulty will put a major stumbling block in the way of efforts to legalize the drug for any but medical purposes, and those will likely be subject to intense scrutiny, despite the revenue the industry would bring in and the corruption which will accompany that. Not that there aren't any examples out there to go by, look at Colorado, and especially the Front Range communities for an example.
Regardless of legality of either intoxicant, there are and will be jobs which require a person to be alert, clear headed, attentive, and even capable of multitasking, which would be interfered with by either. Alcohol has been around long enough to have warnings against "strong wine" in the Bible, and even the (faithful) Muslims just don't. It is a cultural genie that will never go back in the bottle, so to speak.
I question the wisdom of letting another out and sanctioning it.