To ensure that trust actually works and means something, shouldn't the campaigns which accept participants of negative trust be not allowed on this forum?
Why shouldn't they be allowed? Just because a person has a negative trust it doesn't mean he is a scammer or a shit poster. They might be tagged for various other reasons or maybe due to butt hurting a DT member. Seeing the current state of the DT and the members raising accusations to remove some other member I don't see any point in trusting the system.
Negative trust can be request to remove the feedback under your account. All you need to do write a new thread on meta or scam accusation section. If you understand these things then you can recover your account from the negative which are invalid.
More DT members are not a fool to touch the someone's trust and write there.
Once you clear then you can participate on signature or bounty campaigns. Newbies are not allowed to be a participants.