A prot warrior is an AWESOME flag carrier. They can cover huge distances very fast with charge, intercept, heroic leap and intervene. Pair one with a disc priest who uses life grip properly and you can cross midfield in WSG in seconds.

Tanks are better than hunters as FCs because when stuff gets up in your face, you as a hunter can't do a lot. Tanks have awesome abilities to deal with just that. On my prot warrior, a nice shield spike means the rogue opening up on me is taking a nice heaping dose of damage right back. Rend with blood and thunder up ticks on pretty much the whole group that is beating on me. I have shockwave to buy my healers some time. I have intervene with safeguard to buy my healer even more breathing room. I have demo shout to reduce damage I am taking from melee. I have charge, pummel, heroic throw and spell reflect in addition to superb mobility (to leverage LOS) to deal with casters. I have an aoe fear, as a belf prot war, an aoe silence and a fear break on top of my trinket.

There is NO WAY a hunter comes even close to a proper tank spec (geared with resil and mitigation) as a FC - they're just built for very different roles. A mage with 4300 resil can't do jack when two rogues are in their face - they won't even get a cast off. If they iceblock, they'll drop the flag. So all they can do is keep running and if they're cornered, its over. A hunter fares not much better.

A tank with 4300 resil (like mine does) has AMPLE capacity to eat damage. That higher armor helps even when you're stunlocked. And once you get out of the stunlock, a tank has tools like last stand, enraged regen, disarm etc to take the pressure off.

DPS should either defend the FC, or take down the enemy FC - they should NOT carry. Same goes for healers. You can't heal yourself at full capacity while being beaten on.