No, like several others in this thread you are conflating the principle of the freedom of speech with the US First Amendment. They are not the same thing. The First Amendment was predicated on the principle of the freedom of speech. The principle of the freedom of speech is foundational to western civilization, and is applicable to kbin. The US First Amendment is inapplicable here, as it only applies to the government.
When you support free speech, the specific nature of the speech doesn't matter. I'm no TERF, or even close, but I'd gladly fight and die to protect their right to say whatever they believe, no matter how repulsive it may be.
No private citizen is obligated to support freedom of speech — legally that's correct. But for those of us who live in the West, we must fight to uphold western civilization lest it crumble around us. It's a moral duty, not a legal obligation. And once freedom of speech is abolished, goodbye kbin, and goodbye to all of our ability to express any of our thoughts in any context.