@cplenge
Well, let’s take a look at your points.
“Is it really a leader’s responsibility to teach others to drink responsibly?” Is it my responsibility as a leader to ensure an SFC knows how to be a platoon sergeant and act in a manner that meets my expectations? SHOULD we have to…? No, probably not. However do we find ourselves in positions where we need to? Yes, absolutely. Discipline, tact, dealing with people from different back grounds,… things Soldiers can be taught. Why is drinking responsibly any different? Look across your formations. How many kids (he types as a dude pushing 40…) come from broken homes, or homes that offered no real support structures that enabled them to learn those traits? 
“There is a line drawn out there, so why is alcohol on one side and not the other? Alcohol and sexual assaults are very closely linked.” I disagree. I don’t see the drinking as the “reason,” I see people using it as the excuse. The excuse that an undisciplined person, who wasn’t taught discipline in their upbringing or by their peers or superiors, did something wrong.  “I drank too much and blacked out…” or “I had one too many and didn’t know what I was doing.” Maybe it’s someone who is a borderline predator to begin with just using a couple of shots as an excuse for what they did.
I’m not advocating MORE drinking as a way of mitigating sexual assaults; I’m advocating that teaching people DISCIPLINE and PROFESSIONALISM will.
“A different argument is that encouraging alcohol at military events or informal functions is perpetuating a poor culture and creating part of the problem.” From my perspective, mass punishments such as what removal of the option to drink at a function, does more to perpetuate a risk adverse mentality so toxic that it crushes morale and Soldiers’ willingness to serve. You can’t wrap Soldiers in PT-belts, prevent them from doing anything that could possibly hurt them, or prevent all of the ways they can hurt themselves, and then expect them to be meat eating, butt kickers when required.

“What is the lesson we are teaching these cadets?” Simple, handle yourself, control yourself, or face the consequences. Alcohol isn’t the reason for their dysfunction. Lack of discipline is. What about the peers that see those cadets tossing three too many back? Shouldn’t they have stepped in at some point? I mean, it’s been part of every SHARP brief I’ve sat in for the last 2 decades.

I will admit that it’s not right to pressure someone if they don’t want to abide… The way I look at it is, “hey, DD!” You pointed out you’ve heard the line “let’s teach people how to drink responsibly,” however how often have you seen it enforced?  When has there been a BDE ball or dining in, and then a 12 mile Ruck the next morning? I can tell you I’ve done one or four, and after the misery (and several stops to vomit) of that first one, I realized, “hmmm, I may want to moderate next time.” I learned my lesson. Why? Because I was TAUGHT the lesson.

“You can’t tell me that they are trying to teach professional social interactions and drinking responsibly at those functions. If they are, they failed.”  Absolutely! They did fail. They failed the test of being a leader. Guess what, you learned from their failure and won’t make the same mistake. The lesson was still learned.

Total disclosure here, I am a fan of beer, whiskey, and gin. I’ve served this country for over 22 years, and have earned the right to tip a cup. Nothing kills my morale more than someone in charge revoking everyone’s privileges because that “leader” wants to bubble wrap their Soldiers until they pass off their guidon. What’s more, being able to drink at official formal and informal functions that I am FORCED to attend, helps me tolerate people who I would rather not be around!

However back to the original point; the Drink and Think… Drink, don’t drink. Feel pressured? Don’t go and then ensure those who should be aware know WHY you didn’t. It’s your choice. I think it should continue to be an option.

Teach professionalism. Enforce discipline… Everything else becomes easy.