Because we don’t want the SDMB to end up as another “Nazi Bar” when people like him drive everyone else away. Which as a major reason people like him show up in the first place, to drive away everyone else until nobody else is there but the far right or the board shuts down for lack of users.
EDIT: And, they just got slammed by the mods and suspended for a day in the What’s wrong about a lethal military? thread for ignoring moderation.