Why is alcohol not prohibited?

Question

I came across a post on Mi Yodea about the Torah approach to alcohol and a lot of it seems pretty negative. For example, Brachot 40a - 'grapes cause sorrow to the world', Yoma 76 - wine is called יין because it brings moaning (יללה), Bava Basra 90b - you're not allowed to export food/drink from Israel except wine because less wine means less levity, Ibn Ezra says there's nothing more destructive to service of Hashem than wine, etc...

The full answer, with many more sources, can be found here. Obviously there are positive sources as well, but with so many negative opinions, I would think this would be something prohibited.

Additionally, I know Igros Moshe's Teshuva that smoking marijuana is prohibited because of the damage it does to the human body and the cravings it gives you. Science has deemed alcohol even more damaging to the body, and it definitely induces similar cravings that R' Moshe discusses.

So why is alcohol not forbidden?

Answer 1

Rabbenu Avraham ben HaRambam writes:

If God would forbid everyone to drink wine and alcohol as he forbade non-kosher animals and fowl, not all would be able to comply...such a prohibition would also interfere with the benefit of wine and the occasional need to drink it. And if our Torah would say "Drink but don't become intoxicated," it would not work because there is no precise amount. Therefore he taught in the true Torah that it is permitted...but indicated that drunkenness is repulsive and practically forbidden (Hamaspik L'ovdey Hashem ed. Wincelberg p. 556).

This is in turn paraphrased (unattributed) by Rashba (Shut HaHadashot: 367):

ומפני שלא ראתה התורה למנוע שתית היין ולא יוכל לתת שעור לשתיתו עד שתתיר התורה בדרך משל שתיית הרביעית ותאסור יותר משתיית הרביעית וכיוצא בזה, ספר הכתוב התקלות הנולדות ממנו לתועלת גדולה שיהא זהיר ונזהר ממנו כל איש כפי אשר יכיר כל אחד בטבעו

And since the Torah didn't want to forbid the consumption of wine, and could not give an amount to the drinking, such that the Torah would for example permit the consumption of a revi'it and forbid consumption of more than a revi'it, or the like, Scripture related the problems that stem from it, for a great purpose; that a person should be wary of it; each person based on his own self-evaluation.

The Malmad HaTalmidim (Parashat Tazria) writes (and indicates that it is an older idea) that when it comes to intuitive things, the Torah suffices by teaching us to avoid through stories, rather through direct directives. His example, is drunkenness:

כבר קדם לנו כי הדברים שירחיקם השכל יספיק לתורה במניעתם בדרך ספור. וכשם שלא אסרה התורה השכרות בפירוש והספיק לה ברמזים בספורים

Unlike Rabbenu Avraham and Rashba, he is only addressing drunkenness; not any consumption of alcohol. Furthermore, unlike them, he does not say why the Torah chooses to teach intuitive moral instructions through stories rather than direct directives.

For an example of such instruction, see Radak to Genesis (9:20) who writes that the story of Noah's drunkenness is God's way of teaching Man not to get drunk:

היה הספור הזה להזהיר על משתה היין ושלא לשגות בו...בא ספור ממנו בתורה לספר בגנותו

Answer 2

@mevakesh's answer is great, I only want to widen the question a bit and answer from a different point.

1. I wonder you didn't mention Nazir, that brings the Sin Offering (חטאת) at the end of his Nazirut, to symbolize that his avoiding of the "worldly pleasures", including wine, is a kind of a sin.
2. In general, after the original sin, part of our commandments (and therefore our goal in this world) focus on intentional "consuming of the bad" with the sole intention to turn it into good, by using it in serving Hashem. Besides alcohol, sex is a great example of this rule. A supposedly "disgusting and filthy" behavior (ask preschoolers, that did not taste it yet) is turned happily into a great Mitzva(s) and joy.
3. Another example is simple eating, as Rambam rules in Hilchot Deot. This behavior can be "holy", resembling the altar - "זה השלחן אשר לפני ה'" or be turned into gluttony etc.
4. Same with money.
5. So to stay out of trouble Torah could prohibit a lot of activities (listed) and require us to turn into monks, but luckily, Hashem wanted it the other way - to cope with it and turn it into a Kedushah.
6. It falls under "קדש עצמך במותר לך" - Yevomos 20a - **"Sanctify yourself in what is permitted to you". Explanation: If all the things were divided into only two clear categories: good and bad, fully allowed and fully prohibited, there would be no "קדש את עצמך", no Hassidus, no bonuses in Avoydas Hashem. Alcohol, food, sex and other worldly pleasures all fall into this category, of letting the pious to go beyond regular observing. This is called "Hashem's intention", as opposed to "Hashem's commandments".