My view is that this isn't politics. Its being British and upholding British values - you know, that thing that Royalists are so keen on, but can't really describe.
If he was commenting on a plan for taxes, or employment law, or building council houses, that's politics. But he is commenting on whether something is morally right. Something beyond "politics" that involves an inhuman treatment of people who we have decided are the bad guys for no other reason than for political capital and to pander to the more.... let's say "extreme" parts of the population.
A Head of State should not just be there to wave and have pretty children. They should be defending the character of this nation and trying to do something when the government are trying to break international law and ruin the reputation of this country.
I'm with him on this.