Because the US has very unfree speech, despite what someone wrote on a piece of paper in 17-whatever year.
In general, the US ranks pretty low on most freedom metrics, except for the freedom to kill with a gun. In general, the more your country has to tell you you're free, the less free you actually are.
Many other countries explicitly do not have free speech in their constitution, but something more narrow, like freedom of opinion. In those countries, what rights the constitution says you get, and what rights you actually get, tend to be more closely in alignment.
US ranks 78 of 80 on the Free Speech Index here, not sure what your metrics are that make it supposedly "very unfree". Perhaps you'd like to share with the class?
>There has been debate over whether the laws violate the right to free speech and organizations such as the American Civil Liberties Union (ACLU) and the Council on American–Islamic Relations (CAIR) have challenged many of them in court cases.
Freedom of noise might be more descriptive than freedom of speech, in so far as the Western democracies are concerned.
In the US unlimited money has unlimited political power, so free speech, is irrelevant to power distribution, although it might have some academic or personal value for some.
In general, the US ranks pretty low on most freedom metrics, except for the freedom to kill with a gun. In general, the more your country has to tell you you're free, the less free you actually are.
Many other countries explicitly do not have free speech in their constitution, but something more narrow, like freedom of opinion. In those countries, what rights the constitution says you get, and what rights you actually get, tend to be more closely in alignment.