"Speech that demeans on the basis of race, ethnicity, gender, religion, age, disability, or any other similar ground is hateful; but the proudest boast of our free speech jurisprudence is that we protect the freedom to express “the thought that we hate.”"
-Justice Samuel Alito, 2017
The debate on this topic has unfolded over hundreds, even thousands of years of Western political thought. The philosophy enshrined in the Constitution and the Bill of Rights is that in fact we should let this speech go on because the alternative of suppressing it is worse for all of us in the long run. There are people of great intelligence and distinction within American society who still feel that this is true.
(It bears mentioning that while Twitter is a private entity and not bound by the same rules as a federal entity, the mass movement of speech from public to private platforms is one of the biggest issues under consideration.)
The YouTube recommendation engine is a far bigger culprit. It doesn't take many clicks to go from fairly innocuous, but kid-popular stuff like H3H3 or PewDiePie to one anti-sjw or cultural war video and then the recommendation engine will hand hold them right down the right wing extremism tunnel (or continually show up until they do)
I've seen more #KillAllWhites posts than I've seen Neo Nazis