The PC movement attempts the legal and militant suppression of views that depart from a belief in diversity for its own sake. Apparently in itself, diversity is not a sufficiently compelling goal that attracts people to uphold it. For diversity to succeed, history must be revised to show diversity and multiculturalism as preferred outcomes. When historical events did not result in a more multicultural outcome, if discussed at all, it is only in terms of vilification, racism, and evil. The more common tactic is to simply forget to mention events in history that do not support the diversity theme.
Political correctness is often compared to the orthodoxy of the medieval church in its suppression of Galileo, but this analogy fails. The church was the dominant orthodoxy with a long history, and it was resisting the tide of current events. The church was an entrenched power attempting to suppress new knowledge in order to preserve its station. Political correctness is new thinking, unsupported by the totality of history, that seeks to suppress old knowledge in order to take power for its own adherents.
So in the case of the church, it was suppression to retain power; in the case of PC, it’s suppression to take power. Both are wrong, but one at least had the stability and weight of history behind it. And with that historical foundation came the potential for orderly change. PC has no such potential. It can only be revolutionary and this is proved each time it’s progenitors revise history.
Most importantly, revolutions against an organic state of affairs have never worked out very well for the societies subjected to them. The prospects for political correctness are no better.