Think of this in a strictly business light...
If you were a vendor, would you advertise on a website that allows negative feedback at all? What good could come from it? Imagine how many people would post negative things about a vendor they just didn't like (e.g. RRO or Calmini) even if they never really bought anything from them?
What would prevent me, for example, giving RRO a bad review if it was unwarranted? What would prevent me, as a vendor, from rating myself as great?
Any site that looks to vendors for ad revenue, will not likely bite the hand that feeds them. Remember iZook? Have you ever seen a product review on that site, or any Zook website, that basically said, "This part is crap and don't waste your money on it."
Until we have a subscription-based Zook website that does not rely on vendor-ad revenue, you never will.