Trust Ratings Describe the power of profile
There's no relation between trust feedback and the power of the profile, you're talking about trust list where someone can become DT1 or DT2, that have a power to leave a feedback to show as trusted feedback. Also have a enough power if you distrust someone.
Trust is Neutral called Black Trust.
Literally black is just a neutral color and not be called as black trust.
If trust is Black then user can freely participate the Campaigns and he is also considered Legit. If trust is Red then the user is used be considered scam and that user can't apply in any Promotional Campaign in Future untill his total ratings are Black or Green.
It seems like you're saying trust feedback is mainly used for signature campaign, while the truth isn't.
Neutral trust doesn't mean you're legit, actually the use of neutral trust can be used for spammer or merit abuse etc that would make his account doesn't deserve to participate in signature campaign.
While the negative trust doesn't always mean they wouldn't participate signature campaign, if the campaign manager allow it, they can still join.