This is my personal opinion but I meld Tenacity and don't understand why people say to avoid it.
As a tank it doesn't matter how much damage you do, what matters is your survivability. And tenacity literally increases not only your damage but makes you take LESS damage and receive MORE healing.
Imagine how much damage your healers could do if they could heal you up faster and go back to DPSing.
What's the point of melding, for example, double Determination for the damage you don't need instead of melding double Tenacity for damage + defense + higher amount of healing. This stat is literally made for tanks.