Someone that, over time, slanders others, will eventually make their way onto people's ignore list. If you really are as honest as others believe you to be (and as I believe you to be) (and as you present yourself to be) then no one will take such slander without proof.
Just because proof is an absolute defense to libel/slander does not mean that libel/slander lacking proof isn't a revocation of trust-worthy offense in any just society.
Well my point is that just because someone is libeling you does not make them a scammer. There are plenty of examples both here and in the real world when people have libeled others, could not back up their claims with facts and then lost credibility. (FWIW, you still appear in my trust list and I have not excluded you from my list- therefore I personally find your ratings credible)