I am not sure whey would Bitmain account be tagged. If they are no longer with Bitmain then the are no connection left. As they are independent, any action should go against them only. Or may be I am missing a point from you.
I'm guessing logfiles wanted a more visible warning in the hashnest thread which was unfortunately started by bitmain. But yeahhh tagging bitmain would be unfair to them, I share the same thoughts.
Potato Chips is right, My main aim is to help warn the newbies and guest users who might be looking for a clouding mining site. Given that, Bitmain is a popular mining gear manufacturer. Newbies wouldn't twice to join Hashnet if they came across the ANN because of Bitmain's popularity.
The problem is Bitmain has been inactive here since 2019 and there is no way to get them to delete the ANN or edit it atleast.