Political Correctness is not a constitutional issue, it's a cultural issue.
The PC Police aren't robbing you of your right to speak freely. What they have done instead is create a culture of intimidation and "consequences" for anyone who says anything they don't like. Does that work against the spirit of freedom of speech? Yes. But it's not about the Constitution.
"I may not agree with what you say, but I'll defend your right to say it" is not on their minds. They want to shut you up, and they'll find a way to do it.
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I will agree with you Mac (this one time) that "Political correctness" is not a constitutional issue. The government isn't stifling speech so there is no Constitutional issue and that it is a cultural issue, if any.
However, being "Politically correct" is an exercise of their 1st amendment rights as well. However, people want to silence their speech as well. So, it's not like your side is benevolent in all of this.
Your frustration is the power that these "PC/SJW" actually have. Is it formal powers? Nope. But power is just the ability to coerce someone to do something that they would not normally do. Let's use an example of purchasing/economic power.
If people boycott Kohl's because of their relationship of Trump, Kohl's loses money and customers. These people are using their economic power to not shop at Kohl's. No one is forced to shop at Kohl's but people can voice their concerns to Kohl's. The idea is to get Kohl's to not endorse someone that group believes is a bad person.
However, it doesn't always work (Chick Fil-a) for example but if the economic power of boycotting outweighs the economic power of people supporting, companies will end their relationship. Chick Fil-A didn't work because it is in the South mostly and they are in agreement that Gay marriage is horrible.