Because they don't believe the lockdown measures work. From day one its been "the mask protects others from you, not you from others" so anyone not wearing it is a walking death machine to them. That nothing will protect you fully except complete solitary confinement.

I can't be certain of the science on it, but the ideology of it from day one has been "all or nothing, everyone non-compliant is the enemy." Which means to believe "the science" in narrative means to punish and force everyone into following out of fear they are spreading.