Oh certainly, but that does not necessarily mean you "can't say" such things. I would definitely treat a colleague differently if I discover they write a blog a

Oh certainly, but that does not necessarily mean you "can't say" such things. I would definitely treat a colleague differently if I discover they write a blog arguing in favor of Hungarian Notation. Of course people will judge your character. But if such a blog post would get you fired then it would be fair to say you "can't say" it. As an example, Peter Thiel (if I remember correctly) criticized women having the vote. Certainly a controversial viewpoint, but not controversial enough to get him ostracized. But his support for Trump did get him ostracized to some extent. I think this shows the difference between what is just controversial and what is considered unacceptable in SV.