I’m not sure I would go so far as to say that someone who follows Christ out of a fear of hell is dishonest. There is a value to doing what you should out of a sense of duty, or even out of a fear of punishment. After all, that’s how we all learned right from wrong as children (or at least I did), by being corrected, and sometimes punished, by our parents. Over time we learned the value of doing what is right just because it is right.
However, I completely agree that someone that claims to believe just to "hedge their bet" against a possibility of going to hell is dishonest, and in fact not a believer.