There's a case to be made that they shouldn't block anything, regardless of the truth. They're not in a great position to decide which untruths are worth blocking. That, at least, is a matter of opinion rather than a matter of fact.
But the tactic of "Oh, look how oppressed I am on the grounds of my opinion that grass is purple" just looks weak. I'm sure it raises plenty of barking at the sound of the dog-whistle, but that post-post-modernist "everything is a matter of opinion, there are no facts in the world" doesn't make a strong case for putting somebody in charge.