When I was in college I knew a woman who was so nice that many people distrusted her. "No one can be that nice," people whispered.
As it turned out, she was and is.
In her case, due to the odd reaction of others, her niceness had become a negative.
Peter Drucker wrote of the prejudice that some areas of academia hold against clear writing. If a professor wrote clearly - once again the whispers - then he or she must be glib or shallow. Being obtuse was confused with being profound.
Write well and don't get tenure.
These situations say more about the audience, of course, than they do about the actors, and about our ability to create prejudices, especially when those biases suit a personal motive. I've written other posts on how we need to monitor virtues because, taken to extremes, they can become vices. It may also help to realize that even if they are moderate, some people, perhaps in a form of envious alchemy, will transform them into vices.