They can't defend their position, so it's easier to just disable comments. Same way the type of government control they advocate for just silences dissent with either gulag or death. They're always at the ready to throw a bomb in a conservative meme, trot out the tired and beaten into the ground labels like fascist or some variation of a "phobe", but attempt to defend their own positions? Fuhgidaboutit.
They would if they could, but they can't so they dont. Fu*king pu**ies.