I disagree with any kind of discrimination and prejudicial action. I have no patience, however, with people who get wrapped around the axle about relatively trivial and superficial concerns, when there are far more serious related matters requiring attention. This seems to be at the root of our disagreement. You are defining political correctness to include everything people do to combat discrimination and prejudice. I am defining it, based on my experience of its usage, in a much more limited way as I already explained. This more limited definition focuses on what I consider a minor part of the problem relative to the other much more serious aspects of discrimination that remain.
You are right, that is part of our disagreement. First of all, you seem to think that something you find trivial, IS trivial. This may not be the case, as not being a part of a persecuted minority yourself, you are likely to not even realize that something is a big deal to someone.
And, actually, your definition is much more broad. As in, it includes discriminatory, prejudicial, and bigoted language but ALSO includes anything anyone might misconstrue as such, anything offensive for ANY reason, or even anything someone dislikes and prefers to mis-identify their feelings of frustration/annoyance as being offended.
I am calling this out specifically because the factual correctness of statements is never beside the point. It always is the most important part of the point. Ideally statements are both factually correct and courteous. If something is factually incorrect, no amount of polite language or conciliatory expressions will compensate. If it is correct, the language, whether offensive or not, does not change that truth. In either case, the form of expression is secondary to the content.
What I'm trying to say is, when something is factually correct, the truth value of the statement is not the part of the statement that is politically incorrect. The terminology with which you deliver the statements still matters. And while being tactful and/or courteous is usually a good idea (because turning off your audience rarely works to your advantage), being politically correct is a lesser burden. You can be rude and politically correct. You cannot, on the other hand, be tactful/courteous while being politically incorrect. There's a Venn diagram there that you don't seem to want to see/understand.
Yes, there are such things as hard truths, and no amount of sugar coating will make them more palatable. Those truths exist on an entirely different level from political correctness, which generally concerns itself with terminology. If you stop confusing it for politeness or never offending/upsetting people, suddenly the barriers to delivering hard truths that you (and some other people, from both the proponent and opponent camps) have just imagined into being melt away.
By your own explanation here, political correctness tells us NOT to use the commonly accepted term for something, because that is offensive to (presumably a majority of) the target group.
Nope, that doesn't follow. The "commonly accepted term" is not politically incorrect. Unless you think slurs for various groups are actually the commonly accepted terms for them (in which case, I wonder at the crowds you revolve in). Also, just as you get to tell people what to call you and what not to call you, groups can make their preferences known. Now, groups that are powerless/persecuted have very little clout to make others respect their preferences, so we have the much reviled "political correctness" guidelines in place specifically to give more weight to the preferences of groups that are most likely to be ignored.
Changing attitudes and debunking stereotypes through this sort of linguistic engineering just doesn't work, however, and tends to create resentment and confusion.
It does work and it's done all the time. Usually it is done by powerful groups who have the resources to shout everybody else down, or even threaten them into doing what they are told. The only reason people feel "resentment and confusion" in response to rules about political correctness is because they are used to the privilege of not having to concern themselves with the groups in question, and suddenly feel like they've been thrust into a minefield (where these groups, btw, have always lived).
Might I suggest that just because you don't see/understand the importance of something (like the effects of discriminatory language on its targets), doesn't make it unimportant, and just because you are unaware of something (like persecution), doesn't make it cease to exist.
Definitions, and more importantly connotations, will evolve over time as more people adopt a new usage, but this cannot be forced. Stereotypes change by showing people how they fail to correpond to reality. This happens best through direct encounters with people in the subject group who provide living evidence of the stereotype's falseness.
This is both untrue and naive. Do you not even realize how people's preconceptions affect their very perception? This is experimentally proven again and again and again. If you expect to see something, you will find any excuse to see it, or even invent it and retroactively edit your memories. And compartmentalization is a thing as well, where you keep seeing examples of people you know that don't fit the stereotype, but it either never occurs to you to re-examine the stereotype, or you just naturally assume that that even though this person is an X, they are a GOOD X.
I realize you want to live in a world of perfect rationality, but this world simply doesn't exist. Human beings are not very rational. Yes, even people who are dedicated to rationality in all things -- they simply prefer to be unaware of how much irrational stuff they sweep under the rug of post-hoc rationalizations and compartmentalization. The solution here is not to do more of the same but to carefully observe phenomena (especially when they seem to defy your expectations), to be precise rather than vague and tease apart variables that seem to be connected/the same but are actually independent, and to engage in very careful thinking that takes into account the actual contents of situations rather than trying to create sweeping generalizations (under the guise of clarity and simplicity).