I think it's one of the reason people "like" alcohol, it gives them both the courage and an excuse to say whatever they want/feel.

But you seem to be making excuses/explanation for this, I don't agree, what people become under the influence of alcohol is who they truly are, without the mask and restraints. If someone becomes petty/cruel/violent or whatever, you just learned that they cannot be trusted and are a bad person, no needs to explain away with alcohol influence.

In general, drugs amplify or make obvious who peoples are, they don't radically change them contrary to what some like to pretend.

~10% of the population simply cannot.

I'd argue it's a lot higher of a percentage in places like here in Wisconsin.