The banning of dissent under the pretense of radicalism has harmed more people than terrorism — Stalin’s purges, Mao’s purges, heck, even Hitler was just clearing out the seditious members of society who were undermining a strong Germany.
Your arguments, however you mean them, are also those used by tyrannical oppressors to justify the powers they use to commit great evil.
In an (unintentional?) irony, all of those people you cited rose to power and did great damage to their societies by exploiting radicalism in politics.
