I bet if you posted there as a fascist, you would be shunned. But that's besides the point. The point is, sure, it's in some sense coherent, the same way libertarianism is like, intelligible, it's something I can grasp, but that doesn't mean I think it's the right way of going about political talks.
The problem is you seem to think there's like, the right combination of facts, and if you state those facts in order, it will somehow, like, topple another person's worldview? Or something? Something I call "The West Wing myth", where one person just delivers a devastating rhetorical blow and the professor storms out of the room crying crocodile tears, the professor lost his tenure and was fired the next day. He died from refusing his right to free healthcare and realized on his death bed that he had wasted his whole life worshiping an obviously fake religion. Or whatever you seem to think is the result of debate.
And yes, shunning is a totally valid response to extremely vulgar, repulsive views. If someone is going to take away your health care to make a rich person richer, shunning that person is not, like, some weird, extramoral thing to do. We shun rapists, we shun criminals, we shun people who violate the solidarity of the tribe. The fact that you somehow think this is alienable from politics is just astounding.