Yes, reforming users who already want to engage in hate speech is not the goal; isolation is. Look at the pre-internet times, certain forms of radicalization were far less common than they are today because they aren't very present in the in-person community (while those that WERE geographically concentrated, like racism in certain American communities, were still spread in those places).

When the status quo is bad, "maybe that won't work" is not an effective argument against taking action anyway if you don't have a better idea. If we don't take action, we already know we're going to (continue to) have a bad result!