I'd go even further and say stamina > agility > intellect.
In a 30 second fight, I think 3 agility produces less than 1/2 point dps per second for a max of 15 points, including crits. And that's being generous. There might be a little bit of decreased damage from dodge, but then again, not if you stay out of melee. So 2 points of stamina seems like it is worth as much or probably even more than 3 points of agility.
By that logic, toughened leather armor with it's +13 stamina is at least as good a choice for a hunter as blackened defias armor, with its +11 stamina and +3 agility. The +4 strength bonus from the blackened defias armor is nice for a Rogue, but a lot of Hunter's don't care about strength.
I choose the defias armor (along with some other items) because I do like having that extra strength for when I get roped into a melee contest with a rogue or warrior or shaman. I can still win most of the time, especially if I have either or both of lifeblood and agm available, and the other guy does not. And against other hunters who catch me low on health and with my lifeblood and agm on cooldown, I can close in and melee them and totally pwn them, especially the ones that stack intellect.
Meanwhile, the tree bark jacket at +6 sta and +10 intellect seems to me like a poor choice, even for a hunter with the talent that makes intellect = attack power. That 10 extra ap is only worth about .75 dps. In a 30 second fight, that can't possibly justify the loss of at least 5 points of stamina, which is worth 50 health. And if you can get that stamina back, plus much of the dps, by taking the defias armor over tree bark jacket, it seems like a good deal to me. You just miss out on that extra mana that you hardly ever seem to run out of anyway, because you die first, or you drink when out of combat.