I'm fine with it. They're extraordinarily rich; let them spend their money how they want. I mean, nobody is begrudging the super-rich in America their lavish parties, and it's paid for just as much by taxpayers here as it is in England. (YES, really - when super rich people don't pay any taxes at all, guess who bears the brunt of that? That's right, the middle class does! They drive on the same roads we do, but when there's a pothole on that road to be fixed, it's the guy making $13/hr and paying his taxes who pays for that, not the billionaire who pays no taxes at all. Just saying!)
So - to me, at least the royalty paying for lavish parties using money that has come from taxpayer money is more honest than what we do here in America. We may have an illusion that we don't pay for that kind of thing with taxpayer money, but it's just that - an illusion. Life isn't fair, but it's still fun to watch how they live their fabulous lives!