Bear with me for a second:
Imagine I’m holding an apple in front of you. What do you see? “An Apple” - you answer. But how do you know? Seeing is just the act of light reflecting off an object and hitting the receptors at the back of your eyes. From there, your optical nerve transports a blurry and upside down set of individual RGB information. The rest is up to your brain.
And your brain is doing much more than just putting the pixels together into a shape.. It identifies that shape as “apple”. And it knows things about apples. They’re good for you. They are a common fruit. They’re inexpensive.
But here’s the thing: You didn’t invent the word “apple”. You didn’t discover that they’re healthy, common or cheap.
Instead, someone told you.
By teaching you the context to an apple, that person, school, institution or culture wields power. A power to shape your thinking and thereby your world view. And that power is what much of the culture war is about. That’s why so much of it is focused on speech.
Speech is violence. (And so is silence). Speech is dangerous (boy, is it ever). Speech has to be controlled.
You may disagree with the content the left wishes to fill the speech with. (I certainly do in many instances). But I believe they are fundamentally right about the underlying premise - and the leverage gained by winning the struggle about contextualisation.