I don't get this bickering over history in the first place, what has happened has happened and nothing can change it. Also find it strange some people getting offended over something being said about a sahaba i.e someone who was with The Prophets side at one time, but then ready to thrown people from family of the same Prophet because of which that person became a sahaba under the bus to defend that sahaba.
This logic doesn't make any sense at all. Its like you are defending your fathers good friend even after he's killed your brother, just because he was your fathers good friend.
Overall this whole debate is meaningless and not worth fighting over. supposedly the whole world agrees Mauviya was right, doesn't change a thing similarly the whole world agree Syed Ali r.a was right, still doesn't change anything.