Readers must believe in the editorial and review independence of a product review magazine. If the reviews are perceived to be biased they are worthless and no one will buy the magazine. Unfortunately advertising revenue makes magazines viable, not the cover price the readers pay. So publishers are selling a product the readership to a customer the advertisers. Publisher are also paid to produce house magazines. Haymarket publishes Sony magazine and some What Hifi staff work on both magazines. So you get phrases like you do not bite the hand that feeds you and he who pays the piper.
Readers are interested in how products look and sound, they are not buying them to measure with test equipment. They also do not want a course in test measuring and how various test results relate to each other and reflect product performance. So What Hifi reviews give expert opinions of product performance but no measured results, facts to validate the opinions given. Unlike facts that need to be disproved, opinions are easy to disagree with.
Reviews and scores are a value for money ratting, they are comparative and change to reflect changes in the market because most readers are shopping with a budget, looking for what products are the best value for money. They do not want to be doing a cost benefit analysis. To further help readers group tests are performed to give readers an idea of how product performance directly compares. Not using a score system purely based on performance but value for money so a five star product can be out performed by a four star product that is worse value for money gives the opportunity for critics. The choice of what products to directly compare in a group test enables some people to complain that product A was excluded so product B could win, or that it was just another opportunity to promote product B. Changing scores as the market changes, so a five star product someone bought drops to a four star, or a product the magazine only gave four stars to goes up to five stars, gives some people more things to complain about.
People buy power cords and hdmi cables and want to know reviewers opinions. If the magazine does not review certain types of products, casual readers looking to buy said products are not going to buy the magazine. Some people believe all digital inter connectors perform the same, some that all speaker cables of adequate gauge perform the same, some that all amplifiers when not clipping perform the same, a few that CD players when level matched perform the same. If you only reviewed products everyone agrees make a difference to performance you could rapidly end up with a very thin magazine. But reviewer credibility is destroyed when they see and hear improvements people think are impossible. If someone thinks it is impossible for power cords or hdmi cables to produce the effects seen and heard by the reviewers then they conclude the reviewers are deluded, incompetent or corrupt