> Not allowing awfulness to spread could be more efficient than helplessly trying to refute it.

Didn't you just basically say that what is "awful" is subjective? You're basically saying "maybe echo chambers are better".

I generally agree with "people will tend to believe whatever they want", but many people do change their minds, especially as they age. Pushing people into the underground just makes them more extreme.

Also, don't underestimate the power of public mockery. What makes Nazism most unattractive isn't the fact that it's abhorrent from some moral perspective (that not everybody shares), it's the fact that most actual Nazis are total losers by every measure.