Trust is like everything else.
If you see it too often, you begin to ignore it.
I'm afraid this is becoming the case. Trust in general is just being thrown around these days. I'm not saying the OP doesn't deserve the negative rating but, it seems on other notes people have been way to quick to pass judgment and give a negative. I can't think of any specific examples currently but, it's definitely happening.
Since Once this shity person, give negative Trust, he never removes it even if that person is doing no more shit posts or account selling and no second chance is given.
He's removed a lot of his feedback in the past, or at least changed it from negative to neutral. For example, the whole giving spammers red trust thing. That was a forum issue which he took into his own hands and probably thinking about it now wasn't worthy of a red, but reporting those members for the staff to deal with them would of been a better approach.
Negative trust for account sale isn't normally removed though.