This is factually in correct.
Tank stats have no bearing at all on guard or guard switching. These come entirely from your stance. Taunting comes enitrely from your abilities - Stats do not bear on it at all. CC is again entirely from your abilities. Stats do not bear on it. You are just as able to guard and taunt in Rage Spec, naked, but with Soresu as you are in Immortal spec.
As other people have pointed out, the default tank stats on the PVP armour are not good. Defense chance is limited in PVP since you cannot defend autocrits, etc. Shield and absorb do not apply to a variety of attacks. And to make it worse, the default tank set has the LOW ENDURANCE mods/enhancements. So if you are wearing the tank stuff, you are at something like 70k hp, which is the single most important 'stat' for a tank.
If you rip off the mods and augs and switch them for high endurance DPS mods/augs, you gain 12k hp, you gain 37% crit with 60ish surge and you get enough power that your bonus weapon damage goes up something like 300 to 400 points. You lose 20% of defense chance and 40% shield chance. This is an easy trade to make.
12k hp is far far more valuable in real pvp - It gives your healer way more time to see your health move and react. Plus, the extra damage and crit turns you into someone who can actually assist in kills, win duels, and push enemy dps off your healers.
If you go tank stats, your only role in PVP is to sit beside a node and not die. You will not be able to kill, so you cannot take the node. You will not be able to kill an enemy who's attempting to steal the node, so you can only spam "Inc" into chat. Congratulations - You're a pylon.
If you go dps stats and high endurance, you are just as good at defending nodes, except you can flat out kill most enemy stealthers, you can actually protect your healer by PEELING for him, and you can assist on killing their healer.
If you are in a tank spec at all, there is absolutely no doubt whatsoever that min maxing for damage is higher impact and more effective than using the garbage tank base gear.