It does not follow that every reaction to injustice is inherently justice. As an exaggerated example, if the punishment for shoplifting was death, I can oppose that punishment without being in favor of shoplifting.
Obviously, those who criticize overreach of responses to injustice, will inevitably find themselves in common cause with reactionaries who do genuinely oppose progress, whether they want to or not. But that's all the more reason to be tolerant of good-faith dissent: the alternative is no one trusts anyone, and good-faith dissent itself becomes coded as a reactionary trick.
Obviously, those who criticize overreach of responses to injustice, will inevitably find themselves in common cause with reactionaries who do genuinely oppose progress, whether they want to or not. But that's all the more reason to be tolerant of good-faith dissent: the alternative is no one trusts anyone, and good-faith dissent itself becomes coded as a reactionary trick.