Actually nothing in this is all that unusual. When the Singair aircraft diverted to Baku the passengers were stuck in the terminal for a day or so until a replacement aircraft arrived.
At least they were in a terminal, a definite roof of some description, plus they were able to be effectively brought supplies in a more agreeable environment.
I suppose in times of desperation, the aircraft can be like a castle, but given that supplies were at barebones and sanitation was a bit of an issue, it's a tenuous situation and not all that comfortable.
Customs and immigration is a big factor in deciding where to divert.
I'm assuming this is factored into Qantas protocol. It would seem UA have a bit of an oversight in this regard, since they seem to have included CBR. But, I suppose, as others have said, by the time the debris was discovered and landing at SYD was not viable, there may not have been enough fuel to go any where else realistically, let alone circle.
I suppose some boffin now is going to argue that the fuel tanks should now have additional contingency from now on to remove CBR as a diversion port and better account for a case like this. (And that boffin will be rebuffed because, as we know too well in commercial aviation, fuel costs are big bucks).
But seriously, what an embarrassing outcome for this country, especially our nations capital.
What for? It can't be a serious embarrassment "
especially our nation's capital". Most Australians - except maybe the politicians and Canberrans - are well aware of the inadequacy of the national capital's airport to be able to handle any feasible international commercial aviation operations, let alone irregular situations. It's basically like criticising your son for losing a game of tennis when he is actually a rugby player, and the rebuke is meant to be, "Well, they're both bl**dy sports".
Beyond actually providing C&I facilities, which is questionable as previously raised, maybe there might have been a better way to accommodate the wayward aircraft in terms of supplies and sanitation, but that's about it. Part of this probably will - and deservedly so - be directing flak back to UA route planning for having CBR as a diversion airport.
I would agree that for the UA pax to think they could just be easily let into Australia (i.e. immigration) temporarily on account of their situation is unrealistic. I suppose we come back to the argument that "at least they were kept alive and it was beyond control of <blah blah blah>", so shut up about your supposed inhumane treatment....... hey, they're still getting better treatment than refugees...