Hit a metal tube with a rock and what happens...a pinging sound? Hit a carbon tube with a rock..
Not a lot actually, a hollow plasticy sound. Due to the flexiness of carbon I'd say it's just as fit to take stones thrown at it, butted aluminium tubing has weak points which bank on not being hit, if a stone gets launched at them they'll cave in. The danger with carbon is frame damage can be hidden, much like on your average crash, you get up, check yourself, check your bike etc, it's a bit more worrying with carbon as the damage can be internal.
I ride a carbon Zaskar btw. I bet it could take just as beefy rocks bashing it as the Meta, especially in the thinner areas, top tube etc.
