Valid first principles aren't subject to tradition.
In less abstract terms, the case is that abridging speech, especially political speech, is dehumanizing, inherently subjective (therefore unjust), a key tool for tyrrany, and harmful on the whole. It also reduces accountability by limiting the availability of facts and investigations.
None of that says anything about democracy, capitalism, or the West.
And yet, there are clearly potential upsides to abridging free speech. As an example from the Western world, in Germany, hate speech laws are used to forestall the spread of harmful ideologies. I think it's common for people in our corner of the world to believe that abridging speech changes nothing — that people will still believe whatever they want to believe behind closed doors — but I strongly suspect that shaping discourse in a society will gradually change the way people think and behave. Curbing hate speech will make people less hateful; promoting communism will make people behave more communist. (For better or for worse.) Must ethics begin and end with the individual? What if enforcing the structure of society for political/religious/philosophical reasons is collectively deemed more important?
Now, I wouldn't necessarily want to live in a society like that, but it seems to me that "valid first principles" is just a fancier appeal to authority. I'm sure the Chinese would roll their eyes at grand proclamations like this.
Everyone has first principles. There are things everyone thinks are heinous regardless if the context.
The freedom to call for genocide isn't a fundamental right. The freedom to criticize leadership is.
Finally, there are upsides to lots of unconscionable things. At one time, slavery was a cornerstone of the American economy. The question isn't whether there is an upside. The question is whether it's right.
In less abstract terms, the case is that abridging speech, especially political speech, is dehumanizing, inherently subjective (therefore unjust), a key tool for tyrrany, and harmful on the whole. It also reduces accountability by limiting the availability of facts and investigations.
None of that says anything about democracy, capitalism, or the West.