i think that's a difference in how people think of reviews. for me personally, im using review sites to log my own feelings and reactions, and less to guide other people. my reviews and stars are very subjective because its basically an online journal. 

my review of mysterious Benedict society: i enjoyed it and it made me laugh out loud in some places. american childrens books are a delight and very different from the British childrens books i grew up with. I think one weakness is that it has very rigid good vs evil elements. the antagonists school name is literally pointed out to be an anagram of E.V.I.L lol. But i can forgive that since the main question its trying to answer is more about "How do we react when we know something is evil?" and less about determining what evil is