American here, I think you might be slightly off. The views of
Americans as to what constitutes free speech are different than what the 1st Amendment actually says and what SCOTUS is willing to extend it to. There are very few people who look at the reasoning in, say, McCutcheon v. FEC, and say "yes, this totally improves free speech". They look at it and say "this is legalizing bribery and calling it free speech".
Donald Trump literally campaigned on "opening up our libel laws" so he could sue the shit out of anyone who accurately reported his net wealth. The crowd ate it up.
People like the Westboro Baptist Church aren't exactly loved either. In fact, they're a meme. We make fun of them. I'm sure there's a lot of Americans who would love the idea of banning them, and there's groups of bikers who go around running their bikes to shout over them and thus censor them.
America's reputation for free speech extremism comes from the ACLU, which up until recently was the sort of legal nonprofit that would literally sue for the free speech rights of Nazis, a group of people who explicitly reject freedom of speech. They've backed off on this only because it blew up in their faces with the Unite the Right rally.
My personal belief, probably not shared by all Americans and definitely not shared by HN, is that Germany's laws banning Holocaust denial actually improve freedom of speech. More generally, political speech that calls for censorship needs to be treated the same as actual laws that ban speech - i.e. we need to censor them. I mention HN because a lot of tech enthusiast viewpoints are influenced by the EFF, which is run by people who think censorship is just spicy packet loss. Those viewpoints here are actually rather extreme even by American standards.