Can you provide an example where
1) someone was suspected of scamming
2) they provided information to show they were legit
3) the negative feedback did not get removed and
4) the person that left the negative feedback is (still) in the Default Trust list?
Yes, I can.
1) I was never suspected of scamming.
2) My over 3 years of honestly trading here demonstrates I am legit. I was accused of "lying" on the basis of a topic which is under debate and neither party can prove the validity of the accusation. (additionally "lying" has never been an acceptable use of giving negatives from someone on the default trust.)
3) The negative feedback did not get removed.
4) The person who left the feedback is still on the default trust list.
https://bitcointalk.org/index.php?topic=915823.0;allNoted. The actual text in the feedback makes it clear that it does not relate to your trading history. The situation is not perfect. I recall that this feedback was updated and altered many times. Which kind of demonstrates it is self-moderated. I accept that you disagree with that feedback, but in the end it's their opinion of you. And their opinion is generally valued. Regardless of it being valid or not.
I love how people's own standards suddenly morph into some thing else when they can be demonstrated to be in violation of their own values, instead of simply examining ones self and modifying their beliefs/behavior. It shows how much people demand what they are familiar with, right or wrong.
The trust system is designed to be about your trading history regardless of whatever little addendum people want to put into it to pretend it is ok. The fact that he modified his trust only shows he was pressured by the general public to reign in his abuse. He removes it for a while or turns it to a neutral, then next time he is offended he does it again knowing that everyone has already read about it the first time and no one will bother to look a second. That is not self moderation, that is a strategy to wear down the attention of the public of the forum.
Leaving a negative rating for "lying" has never been an acceptable standard for leaving a negative trust rating from some one on the default trust. In fact Beastlymac was removed from the default trust for doing this ONE TIME because a user was attempting to extort him by slandering him with lies, and he was removed.
There are no official rules about how to use the trust system posted anywhere on the forum. It is purposely left this way so that an environment of selective enforcement can be maintained, so that a small group of individuals can dictate what can and can not be said on this forum whilst maintaining an illusion of openness and decentralization.