There's already a standard for establishing trust: the
WoT.
Yet another
review site does not in fact "help" anyone beyond serving as an emotional airing ground for people riled up about someone or other. Scams aren't scams on the basis of having some anonymous agents raging on a review site.
It would also serve as a platform for users to bring their current situation into public to expedite their support request.
Selective service based on who's yelling loud enough is a despicable practice and shouldn't be encouraged.