Reviewing my earlier, I can see that it looks rather 'late night'!
However, my experience of rowdy rugby (and other sporting) crowds and having been a pax for nigh on 50 years tells me that carriers shy away from the problem. They do not want to cause a scene when, for the most part, intoxicated pax are quiet and go to sleep. We know that with the luggage problem, they fear losing customers and so allow more on board than the rules state.
Alcohol is a problem across the UK and it shows up in every walk of life. No one wants to grasp the nettle - see the non activity of the govt in this field.