The problem is that Freedom of Speech does not take into account that Opinion and Behaviour are closely related. If someone wants to have a Nazi 'opinion' of the world, it's not, strictly speaking, an evil thing, very closed minded, ignorant, selfish and stupid perhaps, but not inherently 'evil'.
However, Opinion
controls action, whether you eat an apple or a pear depends on your opinion. Same with Nazi, Socialist, Republican, Liberal or any other opinion, If people want to sit around and think 'Supreme Race' type thoughts, more fool them, but the moment they take any action to confirm to themselves that they are right, they move out of speech and into activism.
That's where 'Free Speech' gets you coming
and going

And heres the real killer, if you
do pick up a gun and shoot them for being evil, greedy, selfish leeches on society, then aren't you shooting them for the same excuses they used to kill others?