I often get three commendations but then again I not only go in as tank, but I explain fights and joke around a bit...basically, I leave an impression. If by the end of the dungeon no one really stood out to me as friendly or helpful over the others, I commend a DD because I know they likely get the least :P. I think you may just be being cynical, there were people like this (and like myself) before commendations, and adding them in changed nothing for me really. In worst case scenario Id rather deal with a fake polite person then a jackass.