Radicalization like the civil rights movement or the LGBTQ rights movement, both considered extremist back in their day? Everyone should; allowing radicalization is very, very important. Platforms that aim to prevent radicalization sustain the status quo which is exactly what a conservative would want.
To quote Doug Gwyn "UNIX was not designed to stop you from doing stupid things, because that would also stop you from doing clever things." and perhaps something similar could be said about the principle of freedom of speech.
No. Try that act on someone else.
Frame it however you want. If you frame free speech as the potential for radicalization than I'm 100% fine with the potential for radicalization. That's part of what living in a free society entails, the right for people to believe in things that you find radical.
So you think platforms should allow for radicalisation?