Because Davis was a grown adult when he started doing this, not a teenager or younger that is already much more likely to be a victim of violence.
I never said we shouldn't try to have a conversation, but there are situations where I cannot recommend putting yourself in harm just for the small chance of changing someone's mind. Davis decided to do that, but it's not everyone else's responsibility or duty to do the same.
Maybe I am just am ignorant American, but Joe is Johnson at all comparable to Trump in terms of overthrowing democracy? I don't recall anyone storming Parliament or Boris claiming any elections were rigged.