If a desire for free speech, to pick a contemporary example, leads to defending the 'right' of the Myanmar military to use Facebook for their coup to oppress the Burmese, pragmatism is probably better.

Consider Qanon people, or NeoNazis, or Boogaloo Boys, etc. It is impossible to prove beyond any doubt that are more dangerous or more wrong than 'normal' people. But if we're being pragmatic, there isn't a reasonable doubt.