I see it as a fight between the social importance of being included as a member of the human race vs the right to speak freely. Both are important, the line is thin.
I hope this isn’t too much of a digression from the conversation, but I have a quick note on your words on microaggressions: they are not "perceived," they are real. This article from Everday Feminism does a good job of explaining it:
The main takeaway: sure, the comments/actions that classify as microaggressions may not have been intended to offend, but the point is that someone from a marginalized group has been made to feel that they are lesser than their privileged peers because of their race, gender, etc.
Personal example: a superior at my last job gave me a task to do that involved simple math, then asked, "Can you handle that?" He may not have been deliberately saying, "Women suck at math," but that didn't mean it didn't hurt or have sexist undertones.
Otherwise, I agree with what you're saying. There's a grey area when it comes to PC; people shouldn't have to censor their opinions, but at the same time you shouldn't abuse your right to free speech by using it to harm marginalized groups. The point of pointing out microaggressions isn’t to say, “You’re not allowed to say anything about black people/women/LGBTQ people/etc., ever,” but to teach others about how their words can be hurtful if they’re not careful, and how a lot of us (minorities included), even if we have good intentions, can have internalized racist/sexist/etc. messages and may accidentally spew them out from time to time.