Some of those from the past that society considered heroes or generally well thought of sometimes turn out to have been politically incorrect - racist, misogynist, homophobic, bigoted, you name it... From ancient Romans and Greeks who turn out to have supported slavery, to upstanding ladies and gentlemen of the Empire who turn out to have uncomfortable views, there may be more of them around than we normally give thought to.
So, what should we do when we find out? Should we call them out for it? Should we stop citing them at all? Where does it end?
It's one thing to take down a statue of Cecil Rhodes, but what about famous people celebrated in (say) Scottish street names, do we rename the streets? Or famous scientists, do we stop referring to their laws and findings as theirs and call them something else?