Because we don't give in to those arguments, we still have free speech in America.....mostly.
Perhaps you should give some thought to who is trying to suppress free speech in the west and in the US. That would be the ADL and B'nai Brith, and they've been remarkably successful in Europe, for example consider ...
"Here is part of Ireland's Prohibition of Incitement to Hatred Act (PICA) of 1989,
"2.—(1) It shall be an offence for a person—
( a ) to publish or distribute written material,
( b ) to use words, behave or display written material—
(i) in any place other than inside a private residence, or
(ii) inside a private residence so that the words, behaviour or material are heard or seen by persons outside the residence,
or
( c ) to distribute, show or play a recording of visual images or sounds,if the written material, words, behaviour, visual images or sounds, as the case may be, are threatening, abusive or insulting and are intended or, having regard to all the circumstances, are likely to stir up hatred."
Read it carefully. This law can be used to prosecute any expressed thought the government chooses."
The 1st amendment has stymied them in the US, here is an account of their struggles with it ...
Racists, Bigots and the Law on the Internet
Hate Crime Laws