“Political correctness is no more than the codification of good manners"

No, it is much more than this. It hides an agenda with designs on power. It sees the requirement of good manners towards those in need of consideration as an opportunity and the means to an end. The true end and real priority is the advertising of the extent and the fine quality of one’s manners and consideration for others. This can mean, in an ironically demeaning manner to those unfortunate others, that they can become, instead of equals, no more than a means to this end. Having accrued perceived virtue in this way the politically correct turn it into the currency of a new power base built on it. Not surprisingly, they sit at its summit jabbing their fingers in denunciation and tyrannizing those who, in their judgement, have insufficient or the ‘wrong’ currency. “Correct” has totalitarian overtones.