But they already had measures in place for those coming back, so did the UK. If people were prepared to pay the cost of hotel quarentine, when it was being applied across the board in the UK, then that's their choice and something they should have been able to face if they wanted to. I just don't see why it needed to be a criminal act to leave when there were already such deterrents in place for those who chose to come into the country at the time. Making it illegal to leave was abhorrent in my view, nothing short of dictatorship. It's moot anyway as they got away with it and now, thankfully, we have been able to leave again for many months.
Hotel quarantine was not applied across the board in the UK.
In the UK during the lockdown periods, it was illegal to leave your home without a reasonable excuse. Whether you were going down the road or halfway across the world was immaterial. According to a friend of a friend who works at Heathrow, a surprisingly large number of people were intending to buy property in the Maldives in February this year, and it was essential that their children also go to view the property.
Australia's rationale is that there is a limited number of spaces for hotel quarantine, so even if everyone was willing to pay there were not enough staff or rooms available (incidentally, this is also why countries like Spain and the US, which by some measures should have gone on the UK's red list, haven't). The Australian federal government has chosen to deal with it by not allowing people to leave for holidays at all; if I were in charge I would have simply said you can leave but you have to take your chances as to when you can come back - that's how NZ's hotel quarantine system operates (though if I were in charge I would have done many things differently)