It would be wonderful for FreeBSD as well as Linux if both operating systems supported capsicum. It would mean that both would have the same sandboxing API. Which would make it more likely for application authors to use capsicum, which in turn increases the amount of applications using it. Also why do you assume Linux's implementation would be poor? there's nothing to indicate that it is. Also capsicum is already implemented for Linux and has been for a couple years, it's just not in Linus's tree[1].