I am a few pages from finishing a pretty bad novel. Yesterday, I found myself thinking of Mark Twain on James Fenimore Cooper: He saw nearly all things as through a glass eye, darkly." The anachronisms are plenty, the inaccuracies striking, the dialogue often implausible, the plot obvious.
Then I looked at Amazon. In round numbers, there are 1600 reviews with five or four stars, 100 with three or fewer. The ratio of five stars to one star is a bit more than 100 to 1.
It is possible to read by passing one's eyes over the pages, taking in the sense of the words, and perhaps remembering the sense but not at all reflecting on the matter read or referring it to anything beyond the piece read. For reading in this manner, I suppose that the book serves well enough, and deserves its rating. There are elements of the fairy tale in, the families lost and found, which can be moving.
It is also possible to think as one reads, and notice that the author seems not to know that Philip Sheridan was an American general, not an English one; that it was Irish, not British, troops that captured the Four Courts; that in 1943 English speakers called the city Rangoon, not Yangon, and that in any case Burma had only a distant relationship to the Central Pacific theater of operations; that near the mid-century natural childbirth was not popular among the prosperous; that train wheels, pace Tennyson, do not run in grooves; etc. Reading in this fashion, one sides with the one-star voters.
Had I the time and energy, I would write a script to collect Amazon ratings for a range of books, to see how my evaluation of quality correlates with a reasonable number of low ratings. Maybe over Christmas.