One could equally ask why a man with his own pub in his back garden would be tempted to do this. It's the musical equivalent of becoming England manager, without the stack of gold bars.
I would offer our spot to David Van Day, thus repositioning the event as a macabre comedy in the manner of Kind Hearts And Coronets as, one by one, David's rivals are dropped into baths of acid, hit by falling anvils and locked into shipping containers bound for Patagonia.
Can't hurt to have Hump, but the song needs to bring out his undoubted charisma. Not sure that those responsible for bringing James Blunt to a wider audience will do that, but it at least makes Eurovision that bit more interesting.