Assuming the Airline has lots of spare cash to offer the Airport this solution on a regular basis.

And had their passports seized and banned from travel for 10 years and served with a life ban from any airline.

I don't know about an airline ban but the length of their sentences would exclude them from e-Visa entry to Australia - for life.
And you don't get told that until you arrive at port of entry.
If you had overlooked that detail then you will probably get turned back onto the next flight out.
They could try their luck with a full visa application but there's no guarantee that they would get one that way either.

I think the USA and Canada have similar restrictions.

The length of their sentences in your case would not be the reason to exclude the e-Visa entry into Australia.

The full visa application would probably have the same result as the e-Visa for the same reason.

I enjoy having a drink at airports at weird hours while in-transit or waiting for a flight and also a drink while in-flight, many others also do this responsibly. Similar that many pilots do not turn up to fly with any alcohol in their system - but some do and actually get to pilot again after being caught.

I am sure I would be happy to fly with a pilot that I knew had been once caught over the limit on duty before - everyone makes a big mistake or two, most of us quickly learn from them BUT not all.

Unless you know something that I do not, then yes it would be the reason.

To be eligible for an Australian e-Visa or VOA, you must pass the character test.
That includes mandatory declaration of any criminal background and exclusion for anyone having a substantial criminal record.

A substantial criminal record encompasses being sentenced to a term of imprisonment for 12 months or more, whether served in full or not.

On application you get asked about criminal history, so to get granted an e-Visa you would need to have answered "NO" to that question.

So on arrival if the conviction is noted by immigration due shared information (and very likely), the entry will be denied for "supplying false or misleading information" this is not taken well under current policy - not the "sentenced period" of character assessment.

Similar is the case with a 600 Visitor Visa application, but a bigger chance the lie would be picked up during the visa process stage and visa denied.

Over the past years I have been following visas Australia has a high tolerance for drinking related issues, so if declared on the applications this offence maybe deemed acceptable for entry into Australia. Violence or drugs is currently a big NO.

I think the two are actually connected. My suspicion (any evidence ?) is that such out-of-control pax on board are typically significant smokers, who unlike anywhere else have been denied their cigarettes for significant hours, from the moment they enter the airport. Yes, they likely take to drink in attempted mitigation, airport bars, in-flight service, or downing their duty-free, but it is the absence of nicotine in their bodies which drives the behaviour.

I suspect the behaviour is entirely the result of how society as a whole has changed coupled with the influx of (dare I say) cheap travellers in our new "steerage class" :rolleyes:

After their performance on this flight, good luck with any further transatlantic trips. They won't be welcome in either Canada or the USA.

They are also barred from New Zealand without a visa.

They should have engaged their little brains before getting drunk.