I thought that Salt and Darkness was somewhat interesting, until I saw what they did with Doton and Hollow Nozuchi. But having the damage from your ground target AoE effectively 'combo' off of certain actions performed when its active was probably considered to be too involved for a tank job or something.

I'm starting to see why they do animation upgrades every so often, and I do think that it's worthwhile, especially now that they've figured out hitstop with Reaper.