I'd have thought 'political correctness' was about compliance with, or deference to, a particular mode of conduct, or expression or institution: it seems like an 'ought' to me, which raises the question who who determines what this 'ought' involves and the extent to which it can be subject to variation or redefinition over time, where an obvious example is in changes over time regarding the use of some language.
One one hand it could involve common courtesy and sensitivity but, on the other hand, it could involve limiting expression and imposing or maintaining authoritarian attitudes and privileges that constrain people so that they conduct themselves in line with the sensitivities and preferences of others - on balance I'd say the risks of being unthinkingly 'PC' for the sake of it, and at all times, outweigh any niceties.