It really just seems like a personal problem to me. Would you trust someone on Reddit because they have good Karma, which is also a good thing? I kind of just live by the philosophy not to send money to strangers online, maybe I'm crazy.
The trust ratings already exist, it's just a matter of showing them and more information is better in this context.
It almost sounds negligent to have potentially important information and keep it hidden.
Its potentially important for members of the site, I agree. Say I wanted to use the name SaltySpitoon as an artists pseudonym as well as my handle here, and I was an active scam buster, and I was painted with all kinds of negative feedback from people I had picked fights with, I wouldn't want it viewable by anyone who didn't have a complete picture as a member here. If you don't have a complete picture of how the trust system works, I don't think you should have access to it one way or another.
On another note, aren't false positives just as likely as false negatives? If you aren't a member here, I could argue that you might not be aware of the practice of sock puppets leaving fake feedback. What if a new member sees positive trust from all of the scammers aliases?
My main point is that having it not visible at all, is less harmful than having it visible and misleading.
*edit* Points to your own trust, Sandy, would you be fine with your relatives or potential employer reading the negative troll feedback left on your account if they did a google search for you? If they don't have any context about the Bitcoin forum, its probably far more negative from their perspective than the people who know to ignore it here.