I think this is often a form of passive aggressiveness. Doing things that make a martyr but don't neccassaryily do anyone real good (real deeds usually go as unnoticed as possible and that's really how the doer wants it, and these deeds are done for another's good, not to make the doer look good, a martyr, a saint. "Oh look at me, how good I am. What a GOOD person I am".