It's not dishonest, it's a clear signal that your opinion isn't wanted. I remember one user who seemed to abuse the feature and they're gone (because of me). Other than that it seems to be used to rebuff spammers and assholes and it works pretty well.
An opinion or belief not being wanted does not imply it's a bad opinion or belief. If one sees an objective belief that they disagree with then I think they should try to refute it not censor it or it's dishonest. If one sees a subjective opinion they disagree with then I think they should just leave it or debate it if they feel like it not censor it or it's dishonest. It doesn't matter if the opinion/belief is offensive or not. An offensive opinion/belief is just as likely to be true as a non-offensive one.It's not dishonest, it's a clear signal that your opinion isn't wanted.