Why don't people like to pick/use Tenacity over Determination?

[MerlinCross]

Hmm, I disagree with that stance, your damage intake only matters as long as the boss is alive, imo you can't really say that the boss's death is mitigation. The moment the boss goes down, it's a totally different situation...

Everywhere I look it's always "Damage damage damage damage damage".

There's no reason to have a couple extra bits of HP when you need that damage to push phase change or beat enrage it seems.