Reviewers almost never give an actual bad review
I somewhat agree, however it is common for reviewers to pick and choose which products to evaluate, often these products are at least average or above- that’s a major reason why fewer negative reviews. The companies chosen are somewhat established so have likely learned lessons on what sells in their market segment.
I wholeheartedly agree @soix with the “usefulness” or lack thereof some of these reviews. Comparative analysis to similar products and the reviewer’s audio chain helps us to determine “value” of the product, without such comparisons we have no reference other than if the reviewer subjectively liked the product or not which is useless.
Often, we have to read between the lines to derive a value judgement. For instance, in HiFi+ review of the Siltech Classic cables here, the reviewer seemed surprised “…first note on the page was “Why haven’t I used Siltech Cables more often?” and “net an extremely neutral and exceptionally detailed cable series. The ‘nothing’ part is just how good that sounds beyond that.” I purchased a few of these IC as I wanted neutral uneditorizing cables and the price seemed fair and within budget.