I'm not sure it works as a prerequisite. I've read most of it, but don't feel like it got me any closer at all to figuring out category theory.

Since category theory was invented to unify abstract algebra and topology, maybe textbooks in those would work instead?

I kind of worry about how much the whole category theory talk on programmer forums is the blind leading the blind. Mathematical maturity is difficult to communicate, and I don't have a clear idea just how far along the ladder of mastery levels you need to be before you can make category theory start paying rent.