Reading is easy, writing is hard. Those of us who write a lot as part of our daily grind enjoy writing non-fiction fantasy on the side. When you review articles professionally and teach students, reviewing fantasy is easy and fun. I suspect that it is not so for most people. It is intimidating and uncomfortable. Of those that do write reviews, without training and experience they tend to focus on the trivial and the rote of grammar and spelling. It is only with time that you learn to regard other writers, some as students to be fostered, others as collegues to be enjoyed, and lastly a few as exemplars to be learned from. I'd say about 0.1% is about right.