In fact, the people most interested in password cracking are usually criminals.
But good luck with the book. It’s just not a hugely in demand topic.
Otherwise you do find plenty of people on YT walking you through hashcat. The first YT Video alone has 7 Million views: "how to HACK a password // password cracking with Kali Linux and HashCat"
I wish him luck, great drive to do this, i hope it works out well enough, books are just in general not easy to sell.
People simply didn't /know/ about them/that they existed at all.
I went to a computer/electronics shop in town and asked for them.
The guy told me: "We don't stock them because people don't ask for them."
I'd say that this is a bit relevant to the entire field of cyber security and a good chunk of development roles. If you're not concerned about how password hashing (which is a key component of understanding cracking) works as developer-- I'm not sure what to say. While not all of the in-depth research is probably needed. It's definitely relevant to many technical fields. I work in offensive security and we use tools like this daily in our industry. And no we are not cyber criminals.