I really don't understand having to show some kind of proof anyway. What would be the point of lying about it? It's not like there is any prize of monetary value awarded if you win.
Honorable people agree with you. Not all people are honorable. I'd be willing to bet there are folks out there cheating right now to get DXCC or WAS or whatever award. Just like there'll be people cheating this weekend when I go race with the SCCA, even though the only winnings are a small plaque you could easily buy at the corner trophy shop. And people probably do that, too. They're in the minority, but they're surely out there.