DRG mitigation action?

[Jonnycbad]

Answer is simple. Look at Estinien. You think a man like him would've thought "maybe I should cast my mitigation BEFORE jumping into a massive Garlean cannon to save the WoL and Alphinaud?" No, cuz he's stubborn and reckless when it comes to engaging the enemy. Dragoons are well known for LITERALLY jumping into the fray of battle, especially against DRAGONS, who probably would just be able to tear though most armor with ease.

If that doesn't help you, then consider this. BLM has the same Casting gear as SMN and RDM, yet they don't have a resurrection spell like the others. Why is that? Because IT GOES AGAINST WHAT BLACK MAGES ARE KNOWN FOR, and homogenizes it, which people hate a lot. Dragoon having a mitigation goes against what Dragoons are known for, and it would homogenize the melee DPS jobs further, which would make people think less of them.

Nothing you say makes any sense because DRG had Keen Flurry
https://ffxiv.consolegameswiki.com/wiki/Keen_Flurry

[Shurrikhan]

Nothing you say makes any sense because DRG had Keen Flurry
https://ffxiv.consolegameswiki.com/wiki/Keen_Flurry

Technically, Lancer did, as a holdover from when Lancer was a makeshift tank alongside Gladiator (snap-/counter-/skill-block-tank), Marauder (high threat, high passive-eHP tank), and sometimes Pugilist.