Flying back from Houston to the UK a couple of years ago, back in steerage, I was dismayed to see a big guy staggering drunkenly toward the aisle seat next to me.
For the next 11 hours he asked for, and was served, beers - 2 at a time. By the time we got to London he'd wet himself and was so drunk the flight attendant checked his pulse when she couldn't rouse him to put his seatbelt on.
I wrote to the airline about all this and their response, in essence, was that it was better for him to be comatose than causing trouble. I guess I agree, but I've always felt they missed the point somewhere.