Most of HN is American. It's on the other side of the world. It has about as much actual effect on the typical American as the just as bad events currently unfolding in Sudan.
Two teams of murderous rapists are fighting one another, everyone has their favorite team, and if someone thinks someone else supports a different team they say "how can you support those murderous rapists! Just look what they did to the innocent people on my side!"
It's an opportunity for people to be tribal about something that, for the overwhelming majority of people, will never affect them the slightest bit.