Because they're incompetent neoliberals who didn't want anything to the left of them to exist because it exposes them as immoral shitbags. What they didn't understand at the time was that when you remove the left from your space you are drastically shifting your community rightwards. Now they have a fascism problem and it looks increasingly like Voat did.

It wasn't really supported by their users either. It was a decision that seemed to entirely come from Antik.