Banning alcohol isn't the answer as it only punishes those who are responsible and serial offenders will always find a way to smuggle it on to their flight, drink to excess prior to boarding or rely more on drugs which people often don't take until they are onboard which they often combine with alcohol.
It's really up to the individual to start taking responsibility for their actions or wear the consequences. Fellow passengers and airline crews are sick and tired of having their flight delayed while some cough has to be taken off a flight and their baggage offloaded.
Jim Jeffries, an Australian comedian living in the USA, said once in a standup that (paraphrased) society can't work on the principle of complete liberalism. That is, we need rules and restrictions in place so that everyone can be somewhat ensured to do the right thing. As put by him, "we have to walk as slow as the slowest walker of society or the whole thing doesn't work. We should be able to take drugs as much as we want, but we can't because she took drugs and stabbed her kids. Similarly we should be able to drive our cars as fast as we want, but we can't because that idiot over there crashed and messed it up for us all."
I guess one can argue that why have we had gun control and a restriction on smoking. I have my own opinions about those, and they don't necessarily line up with the theory that assumes "why not, if everyone is responsible."
If alcohol ends up being banned on board (apart from the fact that Australia, a western Anglophone country, would be one of the few countries in the world where flights must be dry), then stringent, legal consequences should follow for anyone who is suspected of consuming alcohol on board an aircraft at all. If this means breath testing and forced detention of anyone who exceeds a certain threshold, or forced bag searches, so be it, though I doubt crew on an aircraft will ever be granted those sort of powers. You will also run into ridiculous problems for flights leaving Australia, even on Qantas or Virgin Australia (where it is assumed that Australian jurisdiction primarily holds on these aircraft whilst in the air), unless all countries which Australia has air connections with have similar punishments for breaking the dry law.
Banning alcohol on board certainly seems like a be-all end-all to "solve" the problem but carries a huge can of worms and is not necessarily feasibly enforceable.
As far as I am concerned, any sane person should be well aware that almost all medicines and alcohol do not mix well together. Combine that with the effect of air travel and any one who thinks that the effects of combining those three are benign is either a legend or a complete and utter idiot. Intoxication before boarding can be similarly policed, subject to gate checks armed with sufficient legal powers, but those who slip on board should be subjected to greater penalties if they do not control themselves whilst on board (naturally any criminal activity related to their intoxication should be chargeable in and of itself as well as that of voluntary intoxication).
Saw one idiot taken off a BNE/TSV flight last week trying to convince about 9 police that he should've been allowed to travel and that that should look at the video footage of him boarding his previous SYD/BNE flight etc etc. Don't know what that would prove as the fact he was allowed to board his previous flight is irrelevant as he could've been sober then knocked off half a slab in transit in BNE. Again the all care no responsibility scenario rears its head again.
Too bad for him, though if my guess is spot on, police would have likely told him to calm the <expletive> down, let him cool off, then let him go and he was rebooked on the next flight without loss except time.
I'm really not sure how to resolve the difference in my reading and your restatement.
