Dishonest = not trustworthy. Someone who is dishonest often cannot be trusted so that person has the potential to harm others financially or so on. But as long as there are no cases where someone is being dishonest or lying, then I don't think a trust rating is necessary even if it is neutral.

If someone gets a negative or neutral trust rating simply because someone thinks that person is lying without hard evidence to support it, then I don't think they deserve any rating on their trust page. Someone who is identified as lying and committing scam which results in a risk of loss, then the negative tag is very appropriate.