I'm going to take a middle road here. But first I'm going to say that
@Financial.Velociraptor you are too young to be talking like this! You can't tell "back in my day" stories until you're at least 70.
There are two ways "political correctness" get used. Either as a replacement term for "politeness" or as a shaming tactic in an argument to make it appear like you've won the upper hand.
If the people in this thread you were mentioning went on to engage in your arguments or otherwise, then I would say you have a difference in what you consider "polite". And you have to consider "why does it feel like I get called out way more than when I was a kid?" Because you're on the internet, more countries and people than ever have access to the internet, and the group of people you're talking with is more diverse than your hometown or probably state. So what people consider "polite" is expanding and changing.
For the same reason when you're in another country, you wouldn't use a derogatory phrase or gesture just because you didn't grow up with that. For the same reason, when you're on the internet, you're more or less talking internationally. We are somewhat NA-centric here, but even then, the differences between states and regions of the US are huge. So when someone says, "hey, that term is really offensive". I think you should more or less take in at face value, maybe PM them and learn something.
On the other hand, if people only shame you and don't engage in your actual argument, and then continue to point out how you committed a particular "faux pas" as a way of dismissing your thoughts. THAT is "political correctness". An example of this is how Steven Crowder is losing on one of his "Change My Mind" segments
https://www.youtube.com/watch?v=GuNg6oNZbmI. Despite the other guy admitting his wrong and backing out, Steven continues to bring up the fact that this guy used a term in an offensive way. Ie. "Remember this guy isn't PC. He used autistic in a colloquial fashion, so I therefor dismiss all his arguments."
Don't complain about "politeness". Everyone is different and finding places where different people have different ideas can be frustrating. But that doesn't make it illegitimate or PC.
If they were using it as a shame tactic to appear to win an argument, be my guest at complaining about PCness.