Everyone was seeing this as a revenge against the dark lord and his actions towards the Malfoy family, and Albus couldn’t accuse them that they were dark and evil and still followers of Tom. It wouldn’t match to the light side very well. What would happen, if Voldemort returned? Well, the positive side would be that the man would have barely any forces with the changes in the laws and the wizarding world in the whole, but Albus needed to make this as a battle and not a small, insignificant fight that no one would watch. Albus needed to have a war and not a fight that would be ignored by the public.