We all know dogmatists who are more concerned about holding their opinions than about investigating their truth... If they are mistaken, they will never discover it; they have condemned themselves to perpetual error. Human beings (including myself) sometimes use their beliefs for wish-fulfillment. Too often we believe what we want to be true.
I do not have it in for relativism. In many respects I find it a fascinating, even attractive, alternative. It engenders epistemological humility, defeats an arrogant pomposity in belief, even promotes a sort of democratic ideal in matters of knowledge. Perhaps its most comforting feature is that it requires no hard work at all in the matter of justifying beliefs.