In a way, this is what the Royals are for and have always been for. They are, in a way, Johnny come latelys, the media arm of the British State.
Every so often one of them lands in the crap and get pilloried, put in the stocks, so to speak. Very rarely was it the Queen though it did happen (her poor response to the Aberfan disaster in the 1960s, her poor response to Diana's death); more often it would be Philip and his gaffes, I think the Duchess of Windsor, was it? (the still-alive tall slender blonde Catholic one, seen as bit tactless and a bit forward, we hardly hear of her now.) Others, too, on occasion.
It's to make the public feel we have some purchase on the situation, like we have a say in it. I think Harry got wind of this and got out when he could, to paraphrase the Philip Larkin poem, which sums this situation up.
Upstream, someone praises Princess Ann and she seems a good egg. But is she really? I mean, obviously in comparison to the others - the somewhat pale and uninteresting Edward, the self-pitying Charles, the boorish Andrew - but what if it were just her? She might not look so good, she can be a bit snappy, she has no overt charisma; 'they' might come for her instead.
William seems okay but then again, without other worse options, it could be easy enough to make a case against him - some say, well Harry says, that he used his younger brother to deflect criticism, to feed the tabloids stuff.
Andrew is the one being picked off, while those with real State power in the US are not. That's his role and possibly always was, like the sucker in a horror movie who catches on too late, it may well be this was what was always planned for him. Or, you could say, the Royal Family lack a Pam Bondi to shut this down, and wouldn't be able to procure one anyway.