That statement "You were scammed or you strongly believe that this person is a scammer." that appears when you're leaving trust is seriously outdated and really needs to be updated IMO. And since Theymos hasn't taken a stand on members leaving negs that don't meet the criteria of that statement, I'm going to continue to give negs to alts of banned members and similar cases.
Only a fairly small number of people leave trust for reasons that do not match that statement, although they send a very large amount of negative ratings.
If you want that description to be updated, you should advocate for it to be updated in Meta.
If you think that's misuse of the trust system, I would refer you to my own trust page, which is full of negatives from people I've never even interacted with, much less scammed. Some of those negs make very specific claims about how I scammed them for X number of bitcoins or abused animals and many other things.
I have plenty of those types of ratings myself.
I don't agree with those ratings on your trust profile either, and I will tend to not trust the ratings of those who give those kinds of ratings.
Unless there is some amount of evidence that (specific to you) you stole money from someone, I am not going to believe those ratings.