Argentina, France, South Africa, England, Ireland...? they have all picked 6.5s over the years. There's obviously more than one way to skin a cat or they wouldn't do it.
Don't get me wrong, if there was a Pocock then I'd advocate his selection and I'd imagine Jones would pick him in a heartbeat, but there isn't, there's a Kvesic. You don't want to be in the situation where you're picking an inferior player just because he's a certain type of player.
I think where we part on this is the confidence in the coach. It has been put to Jones by the press in interviews about picking a traditional openside, and he has explained how it doesn't work as many think it does.