- It's the best method for approaching truth (for several reasons, one being challenge)
- It allows disputes to be settled ("fought" might be a better term:) without recourse to violence.
If Nazis are willing to fight their corner without using violence then I'm happy because their arguments are easily beaten (hence, why they needed to use violence to gain power in the past).
The problem that social media companies have wrought is not giving people too much free speech, it's siloing opposing views away from each other because it makes some people uncomfortable. Without challenge, speech becomes dangerous, it is not free it is restricted. It's essentially a form of blasphemy law, its effects are just the same, but now we can have several different streams of negative thought growing unchallenged alongside each other because social media has been chopped up into silos.
Insane people can't get into power as long as they can be challenged, that requires free speech. As long as these silos exist there is not free speech and we are in greater danger of insane or authoritarian government.