I found it interesting. I'm always interested in why things do what they do. As in, "If I do this, then this happens." I need to know why this happens because the next time I have a similar, but not exactly the same, problem, that 'why' information can lead me to a better solution.
I've never been satisfied with "do it this way because it works."
It's probably because I spent most of my life in science and need to understand the "science" behind what I do. Just how I'm built.
I am a bit like you Stan, prefering to understand as well as knowing in order to be able to figure out how to do the unusual. Metal cutting is an interesting subject in general; a book that explains a lot more than the paper in question is Metal Cutting by Dr EM Trent. My copy is the first edition from 1977 but the 4th edition was released in 2000 and might be a bit more up to date.