What a thoroughly amusing and entertaining thread!
So to sum it all up, the excuses are:
Australia is too far away, but still close enough to be a realm in which HRH will be Head of State one day.
Environmental concerns prevent HRH from flying, but HRH will be flying to the US and Singapore to promote an environmental cause.
Protocol demands that HRH can't visit any Commonwealth country before the king does, but Anne visited Canada and New Zealand, and HRH will himself be going to Singapore before Charles does.
HRH is a caring father of three and busy with the school run etc, never mind that the children are all on holiday, have a perfectly competent mother and lots of staff to help.
How dare anyone demand that HRH interrupt his holiday, even though HRH's whole life seems to be a holiday occasionally interrupted by work.
And, most recently:
HRH might suffer jet lag!
All of these excuses are missing the point that the president of the Football Association embarrassingly missed the first World Cup that England has been in since 1966.
On the bright side, we got to see a happy Queen Letty and Infanta Sofia, celebrating a glorious win with joyful exuberance. It was lovely to see members of a Royal family being warm and spontaneous, something that no-one can accuse HRH of being. So on the whole, it is, perhaps a good thing that HRH had all those excuses not to attend!