I don't know that I necessarily consider race changes to always be an example of PC gone awry. Some may be, yes. But not all. In the case of Michael Clarke Duncan in Daredevil, I don't think there's a white actor who could have embodied the role as well as Duncan did. The only one who would have come close might have been Michael Chiklis but I think casting was complete before Chiklis really came on peoples' radars for The Shield (that is his show, right?).