I guess we'll have a difference of opinion on this one, but the simple fact is these guys aren't in a normal job. What would happen to a Policeman if he was arrested on a weekend for being drunk & disorderly, or for drinking & driving or for assault.
The fact is the people with the cash (the NRL not the clubs) can put any clause they like in a contract and if the player doesn't like it he can go and do something else.The bottom line is the NRL club grants equals the salary cap and so they pay the players salaries. The NRL registers the contracts and I for one would have no problem with a no public consumption of grog clause from round 1 through to your team is knocked out.
In fact I believe it's inevitable that it will happen.