Your point is very valid etro, no matter how hard you try you will never please 100% of people, 100% of the time, that's just a fact in business.
Everyone has different levels of expectation with suppliers, no matter what type of supplier they are, and despite best business practices, even the best suppliers sometimes stuff up.
I don't think any review should ever be ignored, no matter where it is read, however I believe that everything has to be put in context to create a balanced independent opinion.
I know members who have been dealing with Chinavision for years, some aren't happy, some are completely satisfied and couldn't be happier with the results.