I have come to disagree with the sentiment. The constitution prevents congress from restricting free speech because it is a document written about what congress can and cannot do, not because the authors wanted to argue that restricting freedom of speech was a job that should be left to individuals and businesses.
It is only in response to someone mistakenly arguing to assert their 1st amendment rights in a context where it isn't applicable that this rebuttal even makes any sort of sense--which is not the case for the OP, who didn't mention the 1st amendment or even the US at all. Even here, it is a pedantic argument, such a declaration is a mere technical mistake. In liberal democracies we value freedom of expression.
It is only in response to someone mistakenly arguing to assert their 1st amendment rights in a context where it isn't applicable that this rebuttal even makes any sort of sense--which is not the case for the OP, who didn't mention the 1st amendment or even the US at all. Even here, it is a pedantic argument, such a declaration is a mere technical mistake. In liberal democracies we value freedom of expression.