Because it's a dumb thing to lie about. This guy is part of the U.S. government now, so it's important to know if he's lying to us. This is something relatively inconsequential, but if he lies about more important things, well, that's not something you want in a government official.

Also, I'm bad at video games, but I don't care about that because they're fun to play. When you get someone else to do it for you you're taking all the fun out of it. I learned when I was younger that cheating ruins the experience. So if you're all about winning, that shows a lot of naivety.