The Duke of Edinburgh's Scheme and the Prince's Trust are both excellent schemes. I know as I have benefitted from both. I also know from people who work for them that the Duchy of Cornwall estates are well run and have the right focus in terms of mixing commercial models with environmentalist ideals.
Also, from what I have seen, most people still get excited by a visit from royalty. That can't be a bad thing.
I was at the Golden Jubilee celebrations in 2002 in London. Such a memorable day and great memories for my family and I. Wouldn't have had that without them.