>but it isn’t exactly as friendly to the non-mathematicians as advertised.
i really chafe at criticisms like this given how much effort was clearly invested by those authors in that book being readable - there are ample definitions (and clearly offset), tons of diagrams, instructive examples, solutions to many exercises, pointers to further readings, motivation and discussion.
is the thing that bothers you that there's formal mathematics?
it's a math book. i feel like your same criticism translated into a criticism about a programming book would be something like "this book is too unfriendly to people that don't program because it has lots of code and expects people to be able to read code".
i don't understand what exactly would qualify for you as "friendly"?
>category theory for the average programmer.
that's because despite what people would have you believe - category theory isn't for programmers but mathematicians. so a book like that would be like a book about fluid dynamics for plumbers (read: impossible).