In ARR and halfway through the initial Heavensward story, I mained Dragoon and did get my share of commendations in the process, though not as much as I would have on Warrior or Paladin if I were inclined to those jorbs.

My case was simply trying to be verbally helpful when necessary, not be an ass, know my rotation for solid output, etc. There have been a few occasions where I got triple commendations on a roulette run as a Dragoon.