It is worth looking at the terms of the Memorandum of Understanding between Australia and Papua New Guinea.
It sets the frame-work for the humanitarian horrors which are unfolding there.
Bear in mind: the MOU makes it clear that the purpose of the whole exercise is to combat people smugglers by making an example of the people held on Manus. When government Ministers say they are worried about people drowning, don’t believe them: they are using the survivors as hostages.
If they were genuinely worried about people drowning, they would treat the survivors decently, but there’s no trace of that: not in the MOU and not in the way it is playing out: inadequate medical care; refugees had to queue 7 hours today to get fed.
Just for a moment, imagine that the refugees held on Manus are German Jews, late 1930s: is our treatment of them ethically acceptable?
Here’s the MOU: notice there is no promise they will be treated decently.
You state that in the MOU “there is no promise they will be treated decently”.
However, the “deal between Australia and PNG” contains clear “commitments” (promises) to “dignified” and “respectful” treatment “in accordance with relevant human rights standards”, including “the Refugees Convention”.
“15. The Government of Papua New Guinea will treat all Transferees who it permits to settle in accordance with the Refugees Convention.”
“Commitments
17. The Participants will treat Transferees with dignity and respect and in accordance with relevant human rights standards.”
Furthermore, your claim that “if they were genuinely worried about people drowning, they would treat the survivors decently” is a non sequitur; the conclusion does not logically follow from the premise.
If a mother was “genuinely worried about [her children] drowning”, she wouldn’t facilitate them getting into a boat and then “treat the surviving children decently”. She would take actions to stop them from getting into the boat.