or the other way of looking at is when every one does leave you have groups of alcohol and testosterone filled young men all leaving at the same time roaming the streets trying to get home or something to eat
guys who have been in the club all night without leaving during the night for something to eat or some fresh air.
The other problem with the foolish idea is that often in crowded venues it can be difficult to spot those that have had to much and maybe should call it a night.
a situation made worse if no one leaves.
If people are coming and going those that have had to much will normally be stopped when they try to re-enter and not let back in.
