> if you are willing to put together a desktop workstation with your own hands from components you hunt down individually at online sales and install the free Linux, you will not spend even half of the cost of a Mac Pro
Show me this put together beige box, and I will show you a machine with missing features found in the Mac Pro. Then you will say, "I didn't want that stuff, I would never use it," but when added in, the prices will be within a close margin.
> when [all Apple-chosen hardware features] [are] added in, the prices will be within a close margin
I do see your point, but even if that's so, the problem of Apple hardware inaccessibility to an average computer hardware buyer cannot be considered as "resolved" or "unavoidable", but only pivots from the circumstance of "Apple forcing high profit margins on hardware buyers" to "Apple forcing a set of (unwanted, yet costly) hardware features on hardware buyers" (through the lack of appropriately varied hardware models and hardware configuration options).
Which is too bad, because if Apple hardware was appropriately inexpensive while delivering the features that I do care about, I would probably consider switching to their hardware and macOS as my primary O/S. (... But then again, maybe not - I really like the latest Linux KDE/Plasma.)
Then margin on Macintosh hardware is notorious for being slim. Where it seems they make their money is in the options for more RAM and larger storage. But Apple doesn't make much profit on the base configurations of any Mac, and until they started charging a premium for more RAM or storage, Apple didn't make much profit on any Mac configuration. Apple's history bears this out, as Apple only started growing wildly with the introduction of iPod and iTunes Store, and again with the introduction of iPhone and iPad.
To me, because those expensive extra features on a Mac are not optional, I still consider it way overpriced. The only reason many of those little extra boosts are so expensive is because they simply aren't broadly in demand.
Show me this put together beige box, and I will show you a machine with missing features found in the Mac Pro. Then you will say, "I didn't want that stuff, I would never use it," but when added in, the prices will be within a close margin.