K&R was an excellent introduction (short, expensive, valuable). However, I think I learned more about the why of C from reading Harbison & Steele, "C, A Reference Manual". It was a book for compiler implementers and programmers, and went into some of the design decisions, which really helped my comprehension.
As I read it*, the argument is over the 37 verbatim copied headers that define the API. That's like Oracle making a beautiful (ahem), elaborate sign explaining how to ring their doorbell. Google made their own doorbell but copied the sign, embellishments included. While the content of the sign is "fact", the decorations are arguably product of a creative process.
While I'll have to wait for better analyses of the ruling, I think we can take away that if you're reimplementing a library, you might want to reimplement the headers too.
* IANAL, and I'm not speaking for my employer. I only scanned the ruling.
Disk drives OTOH have no fundamental advantages over flash...
Flash has 1 transistor per cell (1, 2 or 3 bits). HDDs have 1 transistor per 10^10 bits or so. (Plus the interface transistors in both technologies.)
Real Programmers don't eat quiche. They eat Twinkies and Szechwan food.