those people do radicalise others into committing murder.
You mean like the 50+ people murdered and entire neighborhoods razed to the ground during riots started by leftist disinformation? Like how covid hysteria led to teenage girls being hospitalized just for not masking hard enough? Or how Jewish professors have been forced to flee their campus by armed mobs? Female professors hospitalized with neck injuries after being attacked for attending a talk campus leftists disagreed with? Jewish students forced to lock themselves in an attack and barricade the doors against violent mobs incited to attack them by decades of indoctrination claiming all Jews share responsibility for everything bad in the world, even police brutality?
It's one thing to not take action to prevent them speaking elsewhere, and another to provide them with a platform and a revenue stream.
And your argument falls apart in the age of monopolized infrastructure. People have tried to create new websites, they were denied hosting. They tried to start new providers, they were denied access to server and backbone infrastructure. They tried to build new infrastructure, they were denied payment processing. They tried to handle their own payments, they were denied bank accounts.
Where does your totalitarian ostracism end? Even heroically successful black antiracism activists like Daryl Davis have been called nazis and threatened by woke mobs. Should he have to invent an entire parallel currency, banking system, telecommunications infrastructure, server farm, and webhost from scratch just so he's able to exercise a fundamental right?
You don't have a problem with any of this, you just want to be the one doing the murdering.