It's most interesting to read the comments about Australia retaining the monarchy or becoming a republic. Thanks for that. No one mentioned, no one left out.
Not being an Australian, I don't have an opinion whether Australia should become a republic or not.
I do however find the behavior of the PMs unprofessional.
Australia is still a monarchy and as such King Charles is still the Head of State - on top of that he is an honored guest.
The politicians can be republicans all they want and argue their points all day long, that's fair enough IMO. But when the show is on, they have a public role to play as a part of their office. So refusing to meet with King Charles is unprofessional, it's insulting to both King Charles as a guest as well as the nation he de facto represents (which is predominantly the UK). It's disrespectful to the Australian monarchists as well as the democracy. As long as Australia has not abolished the monarchy by democratic means, they just have to accept the fact that Australia is a monarchy or they should not have accepted the office they hold.
What is even worse, I dare say, is that it is stupid behavior. Such behavior reduce support for their cause rather than increase support. They are pandering to their extreme voters, rather than trying to win over more by acting professional like statesmen.
If they truly cannot bear to be in the same room or shake hands with King Charles, a man who is merely a representative like themselves, then they should step down from that office. They forget that as elected PMs they also represent those who did not vote for them.