Here’s a quote from the Preface to Fowler’s Modern English Usage (the link is to the most recent edition, with the new title Fowler’s Dictionary of Modern English Usage):
The mystery remains: why has this schoolmasterly, quixotic, idiosyncratic, and somewhat vulnerable book, in a form only lightly revised once, in 1965, by Ernst Gowers, retained its hold on the imagination of all but professional linguistic scholars for just on seventy years?
R.W. Burchfield — Fowler’s Modern English Usage
I find the prefaces of my grammar reference books to contain some of the best writing around. Part of the reason for the excellence of these superbly crafted essays is that the preface writers (who are usually the editors of the book) have been deep in the thicket of the written word for decades. But I suspect the principal reason for the excellence of these superbly crafted essays is the passion these editor-authors have for their subject.
That’s why I always read—and often reread—the prefaces to my reference book; there are linguistic jewels to be mined, and I am a miner.