Powerful people often threaten those who are less powerful when they abuse them: If you tell anyone, I will ... ruin your career, kill you, hurt your family, prosecute you; harass, humiliate and persecute you (e.g., rape survivors), etc. That's why we have some anonymous reporting in some situations, to provide liberty and justice for all, not just for the powerful. It's the same reason anonymous speech seems an essential civil right to many at HN.
These days, a common reactionary rhetorical technique is to frame the desires of the powerful as if they are the vulnerable and powerless. What about their plight? ;) At the same time, insisting that anonymous reports - journalism, accusations, etc. - are invalid or violate their rights have long been a tool of the powerful: Make the vulnerable person expose themself to retribution, which also intimidates future victims from speaking.
There are no easy answers, but one approach is differentiating a report and a prosecution. For example, anyone can make an anonymous police report; if the subject of the report is to be tried and convicted, then the accuser needs to come forward.
How else do we protect the vulnerable without anonymity? How do we stop the powerful from running roughshod over them, unchecked?
> Anonymous accusations are a fine way to harass and intimidate anyone you disagree with or have a grudge against.
As discussed, that is not at all the only use for it. Do you have evidence about how common that is, for example at Stanford?