Because Flat-Earthers aren't like...dangerous? 

His exact wording was "Russians were the real war criminals, not the nazis" and buddy, if he doesn't think the mass oppression and murder of Rroma, Jewish, Gay and the disabled doesn't count as a warcrime, then he's fucked in the head. 

Listen pal, I get it. You don't like drama. I don't like idiots. But you're more willing to have him here than me.

Pretty fucked up.