IB
More should be refused at the gate
Plenty have this year in our "crackdown", and I mean PLENTY!
As you rightly say, a big issue is with people drinking heavily whilst waiting in the airport. The problem is that this alcohol intake doesn't have an immediate effect, it takes a while to get into the system fully. So, having drunk up to the time to present themselves for boarding they appear quite OK, 20-40 minutes later, they deteriorate, by which time the amount of oxygen they are breathing has now reduced too.
This policy should be applauded as an attempt to stamp out this minority who just can't abide and think that rules don't apply to them.
If I'm not mistaken I seem to remember a long time back when flying from Canada (I think), that any duty free drink was put in a sealed bag and then delivered to the aeroplane to prevent people drinking it between buying it and boarding....The next step I suspect.