I appreciate the reference to the 'proving too much' fallacy which tbh I haven't seen mentioned before.

I think there's a misperception (in most responses) that I'm bringing up the paradox as a complete justification for PayPal's actions, which I'm not. Rather, it's a direct argument against OP's apparently free-speech absolutist position. Essentially, so many people here on HN are saying "how dare anybody draw the line anywhere, because the act of drawing the line is actually a form of oppression."

Perhaps from the perspective of someone who thinks purely like an engineer, this black-and-white framing of the issue makes perfect sense. But by the measure of real-world consequences, that's simply not true and perhaps it just takes some time and life experience to realize that. It did for me - I used to be much more of an absolutist on this stuff but I've seen, over the last three decades, how conservatives have used misinformation to change public opinion on issues that should be clear-cut. Simply arguing against them doesn't work because it's much easier to spread emotionally-charged falsehoods than to sit people down and give them the much longer, more complex, correct information.

And to a point you made, it's much more difficult now than it ever was to know if anyone's making the free speech absolutist argument in good faith, because the internet is now rife with people who spend time in the chan communities and are completely aware that "pro free speech" is an easy and effective proxy for "I can share my Nazi-adjacent views with no consequences" that easily tricks moderates into fighting for them.