If only hylo-morphism was so simple...I just spent a few months studying the concept, and let me tell you, Aristotle's form/matter distinction is so strange and complex and difficult to "boil down." Really, it takes a close, and very slow reading of the Physics (as well as other Aristotle texts), and a lot of reference to secondary sources, to get a handle on those difficulties. I'm not sure if this is an apt introduction, but I understand many people don't have the time to, as I said, read these texts carefully and closely, and they want an easy answer that conforms with the logic of the world they are already familiar with. But then you wouldn't be doing philosophy.
It's like Hegel said, when you want to study philosophy in earnest, you must "wear the vestments of the high priest," and never shy away from confusions or contradictions.
First, I might recommend the Metaphysics before the Physics. Second, I think reading the original Aristotle as a novice and alone is perhaps not the best move. I think it is best to start with a commentary or something more pedagogically suitable. Contemporary expositors like Edward Feser or David Oderberg write lucidly and approachably on the subject (see “Scholastic Metaphysics” and “Real Essentialism”).
That never said, it takes time to understand this stuff, especially when all sorts of bad intellectual habits must be broken.
Asking from genuine curiosity: what sort of bad habits did you encounter when reading philosophy?
I can identify with this from analogy: I recently started learning a guitar solo that is probably a couple of steps above my current skill level, and it served to reveal some bad fingering habits I had that never became a problem until I started to push the limits of my playing ability.
"Mainstream metaphysics" means categorialism. Everybody knows about genus/species hierarchy.
"What is the relationship between categorialism and hylemorphism, Aristotle’s other major ontological theory? Where does matter fit, if at all, in the categorial scheme?"
I think there are 2 things at play here.
1. It's an old old idea, and the presentation was cogent in ancient times, but takes a lot of effort to get the meaning as expressed at the time. A poor example, because time goes the wrong way, but I'll still offer it, since I think it has some of the flavor of the problem. I theoretically could hand wrap wire memory to run python on a relay based computer, but I'm not going to. and, what would I lose in translation?
2. The form and matter split is probably the core, but I'd guess there are lots of subtleties and consequences of accepting or rejecting the various parts of the argument that the article sorta breezes through.
I don't know though. I'm not a historian or philosopher.
It's like Hegel said, when you want to study philosophy in earnest, you must "wear the vestments of the high priest," and never shy away from confusions or contradictions.