Well, personally, I have posted on occassions after a few drinks. Not at a stage where I was totally intoxicated.
I have found myself to be very emotional in these times and needing support. Or, being in an emotional state of mind, which allows me to really express what I'm feeling.
And at the same time being able to really get into a thread and understand a person's post properly, therefore writing more insightful replies.

I do understand that there could well be times where judgement could be drastically impaired, and the wrong things could be said negatively affecting others - this is not appropriate.
I don't have an answer as to how to control these situations.
But, as long as it's not excessive use of stimulants - I don't think there'd be any issue with posting.