I hope you're aware that this particular argument only reinforced people in their existing positions, and has no chance whatsoever of convincing people that don't already agree with you.

Some times you can not change peoples mind. Especially when they are bad human beings. First step is to point out their evils. So that they can be ostracised from polite society and discussion. This is the tactic they have been using. So goal is not to change them as you can not change evil. It is to get the rest to kick them to curb.