Sure, but my larger point is that I believe people should strive for free speech maximalism even in their private dealings, and even within the private dealings, we should strive to make the consequences we impose minimally "dangerous". There's no bright lines to be had, and everyone will have different limits, and every situation will have different criteria applied to them. But overall I'd rather err (and see other people err) on the side of being too permissive rather than not permissive enough. On the scale of less to more permissive, I'd probably argue that the order would be something like "friends", "business partners", "employees", "contractors". The less likely you are to be inviting someone over for dinner, the more permissive you should probably be over how their outside speech impacts your business dealings with them.
People only change by exposure to new ideas, and if all the "bad people" and all the "good people" never mix, then what hope do the "good people" have that any "bad people" will learn to think differently?
Basically, I really don't want to live in a world where it's normal for my boss to go trolling through my HN comment history before deciding whether I get a promotion or not, no matter how much of a right they have to do that. I'm not ashamed of the things I've said here (to the best of my knowledge), I just don't think that having a discussion with other people, about topics that don't directly bear on my work should be used when determining how to treat me at work. I am not so conceited as to think I am right all the time or that my bosses would agree with every thought I have. Which is why I have these discussions here, with other people engaged in the topic and not at work, with my bosses who weren't talking about the topic in the first place.