I don’t think someone “tagging” scammers should be a criterion to include them in your trust list unless they have nearly 100% accuracy and you can otherwise trust the person. I have seen a number of accounts over the years that were used to call out scams, however they often had very low accuracy, relied on conjecture, and often parroted what others already said, and many times turned out to be less than trustworthy people. Adding someone who “tags” a lot of scammers without substantial trading experience will also lead to poor ratings quality and it will be difficult to authoritatively say they can be trusted.

As mentioned previously, having people on your trust list that left you a positive rating should not necessarily be a bad thing as this is evidence you know the person well enough to trust them.

Also, someone no longer being active is not necessarily a reason to remove them from your trust list as prior trust ratings are not invalid because of this.