Yup. He's... socially inept, but Vegas is his hometown and I'd expect him to support that team.
Well he grew up in Vegas.
Honestly, of all the things that Nats fans crap on him for, that one is the one I understand the least. He grew up in Las Vegas. That's his home town. So yea, when they finally get professional sports team, I'm totally okay with him being a fan, even when they play DC. I'm sorry, no one here grew up a Nationals fan. But here we are, adopting them as our team, none of us growing up rooting for them.