I believe that the culture of "Political Correctness" began on September 28th 1987.

Beepster
Nothing wrong with not being unnecessarily offensive/insensitive/tone deaf. I've purged words and faulty/hurtful ideas over the years after either learning their true roots/meanings/intent/end game. If I can avoid making someone feel like crap or uncomfortable simply by avoiding certain words I will (within reason... eg: arseholes may not apply).
 
I've never liked the term PC and it was never used amongst any of the libby lib "SJW"s I've been surrounded by most of my life. I pretty much only ever see it used as a cudgel against pretty solid arguments for general compassion and empathy for your fellow human.
 
It's also kind of infuriatingly hilarious that the people who walk around whacking others over the head with that term as a pejorative generally flip the hell out over the tiniest little slight (imagined or otherwise) against their own delicate sensibilities.
 
It's really quite simple.
 
DBAD*
 
*credit to Wil Wheaton

 
It's not quite that simple really though is it. I'm sure nobody objects to the idea of refraining from the use of derogatory names and epithets to describe people. If only it had stopped there. The trouble is that it's created this culture in which anyone can claim they are offended by anything, regardless of how ridiculous the claim is. You don't even have to give a good reason - simply by virtue of the fact that you're offended, everyone has to tread on eggshells around you and woe betide anyone who forgets what the "correct" term for something is. 
 
The result is a generation of kids who seem to have nervous breakdowns if someone so much as looks at them wonky. And then you have terms like "safe space" being bandied about universities and colleges. You only have to observe some of the discussions which go on on sites like Buzzfeed or Jezobel to see just how far down the rabbit hole of utter derangement some of these kids have gone. 
 
A great example of this is the concept of "cultural appropriation." You have kids foaming at the mouth over the idea of a white woman wearing her hair in braids, or a white man sporting dreadlocks. I have an old friend with dreads and I've seen him get into discussions online with people who think that his hair style has been "stolen" from black people, despite the fact that dreads have been worn by people of cultures all over the world for centuries. You should see how deranged some of these kids are. They're calling him a racist, a thief, threatening him and generally displaying just how off the rails this whole culture has become. 
 
Another example: I recently got into one of these discussions on Buzzfeed. The subject was a story which broke a few weeks ago in which a female presenter discovered she was only being paid half of what her male co-presenter was getting. Naturally the whole thing was touted as an example of rampant sexism. I simply pointed out that these salaries are negotiated by the star's agent, and that these kinds of negotiations can swing wildly one way or another depending on a whole host of factors - how aggressive the agent is, how aggressive the star is about wanting a pay rise, what kind of bargaining chips they're bringing to the table etc. Maybe it was common knowledge that the male star had been getting offers from other networks, that sort of thing. My whole point is that while it might be sexism, there are factors which suggest that judgment should be deferred until everything's out in the open. Oh boy. I was torn apart by the social justice warrior crowd, calling me a sexist pig, an "enabler" who was obviously trying to "man-splain" how TV salaries work to women I obviously thought were inferior to me. Basically, regardless of the line of reasoning I used (which seems pretty reasonable), I was voicing the "incorrect" opinion and thus I had to pay. 
 
The net result of this kind of insanity is not a more harmonious society, as proponents of political correctness (or whatever you want to call it) will have us believe. No, it's turned society into a collection of warring tribes who resent each other. It's creating more conflict, not less, and much of that conflict is firmly rooted in the Twilight Zone in terms of how rational it is. It's created a situation in which everyone wants to promote themselves as a victim because of the political currency to be gained from victimhood. Frankly there are way more important things the human race should be concerning themselves with.