If we leave negative trust to shitposters I think people can end up ignoring the feedback left to scammers/untrustworthy users.
I agree. I only tag accounts as shitposters if it is obvious to even the brain dead fool. All one or less liners, no contribution to the post.
To date, I have left negative feedback for
61 shitposters, and most, if not all, have never complained about it.