The problem with the ever expanding list of what people deem negative rateable, is that in a lot of these cases there is no evidence, it is left to the judgement of the individual. So essentially you have a bunch of people running around as judge jury and executioner with no recourse for those swept up in it wrongfully. In the end all this results in is making the negative ratings meaningless anyway giving cover for actual indisputable fraud. You don't have to like it or agree with it, that doesn't mean you should negative rate over it.
This whole "well what about this and what about this" game is simply an attempt at making it look like the sky will fall if we don't have a huge nanny state full of wanna be forum cops shotgunning negative ratings. Freedom and security are exclusive concepts, and your goal of absolute security is unattainable. Lets stick to what can and should be enforced and leave the nitpicking to the lice infested before these trust mobs demand rectal inspections before they give you permission to use the forum uninhibited.
You have some valid criticism. It is often difficult to see the difference between those that have been given a negative unfairly complaining about it and those that have been tagged fairly but continue lying about their plight.
I like LoyceVs suggestion:
I'd like to add to this topic: before leaving feedback, ask yourself if your feedback makes the forum better, and (if applicable) is it worth destroying someone's reputation?
Especially in the scam accusation section of the forum there are quite a few threads of accusations where there is no real proof or a commercial dispute with the same people repeatedly posting in the same threads and bullying anyone that has a different opinion.
The organisations complained of are also not so squeaky clean that they are worthwhile defending in such circumstances.
I think the difficulty is that amateurs with usually good intentions do the "investigations" and the "proof" provided is worse than circumstantial. Positive or negative trust still is just someones opinion and it is for the viewer to interpret the reliability.
There is not lot that can be done about that. Trust is that individuals perception and interpretation of the situation.
The way I have constructed my custom trust list is to include those that I feel confident that do a quality job with research before tagging and will remove a tag if evidence to the contrary comes available.