I care what the author thinks they were expressing because it matters if you want to know if the did a satisfactory job of expressing it, or why they didn't. But whatever you can do to learn something useful from someone else's work is valuable regardless.

Some people fall in love with things and make their whole life perspective about things like this. I'm sure one could study a rock and learn how to be a great person if they have the mind to do it. On the other hand, people tend to think The Terminator is some kind of prophetic documentary ALA "fiction has some basis in truth" (as though the reality didn't have a better claim to that description.) So I'm wary of anybody who takes a work of fiction too seriously, except in the academic sense of being a good communicator.