Why should anyone care what the inbred prat, Charles, has to say about anything? He has already proved his amazingly poor judgement in how he handled his first marriage and his extramarital affair. Only a very small minority of devout royalists think he is relevant to anything going on in the UK and in the world. The only time anyone should take note of anything this buffoon says is when he meddles into politics. When this happens, he should promptly and strongly be reprimanded. Royalty has no place in politics. For that matter, royalty has no place in the modern world.
Charles can say whatever he wants privately, and frankly, there's no law against his (or the monarch's) expressing a point of view publicly, though the general view is that the royals should not do so, that publicly they should remain silent on matters of policy.
But since Charles isn't yet the monarch, he is actually less restricted than the Queen is, and he certainly is not required to muzzle himself in his private letters and conversations.
This is a private matter, which was not made public by the Prince of Wales but by the recipient. It has nothing to do with political matters in the UK which he does not comment on in public.
The British people (not the royals) elect a government. If they don't like what they voted for, that is the problem of the electorate and the responsibility rests with them. As you say, blaming royalty for your own shortcomings is a classic cop out.
The Queen is not supposed to be political. It is wise for other royals not to be seen as political because they have to represent whatever government that has been elected. Royals can speak out about issues, though. They do try to be in the background and talk to elected politicians about what they have heard people say about different issues.
The Queen and senior members of the Royal family must not take political sides. Charles can have a view,but he cant say "Mr Cameron is doing a great job" Or "Ed Millivant is rubbish"
He often oversteps the mark and hence will be a BAD KING.....NOT his place or role...
so its not the royals place to speak out, to help their own people. so how come Charles can comment on matters concerning Iraq?