Earlier quoted context omitted.
It's an unexplained phenomenon. I know of a Russian author, Dontsova [1] that is the same: hundreds of shitty detective novels, immensely popular. [1] A wikipedia article, as badly written as the books: https://en.wikipedia.org/wiki/Darya_Dontsova?wprov=sfti1
Maybe it’s best understood like a Big Mac. One crappy burger after another, eaten for eternity because they are reliably average. There’s money to be made as a serial provider of homogeneous sustenance
We think readers should be a smarter crowd--and, thus, more upscale in their choices--than TV watchers and popular music listeners (as both groups comprise, roughly, the general population). This is possibly the case, but it seems to be cancelled out by the massive time investment involved in seriously reading a book: eight hours for a typical novel, as opposed to an hour for a TV show or 3 minutes for a pop song. The high cost of exploration means that the book world has the same problem and, unfortunately, the processes and people who are trusted to filter for quality, quite frankly, don't. Traditional publishers follow the market and "book buzz" is built from the opinions of highly influential non-readers.