I feel that while the author shouldn't be the arbitrator of what the whole work is about, they should have a say in what it's not about. e.g. if Lewis Carol would have stated that Alice in Wonderland is not about drugs; then the public should respect that and stop telling everyone else that it is. Following that thought to its logical conclusion, if extremists of any kind praise a work for promoting their view while the author denies that it does; with whom should we side?

I do think there's an interesting discussion to be had about it.

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.

The idea of "meaning" is synonymous with agreement. Individual words "mean" things because we agree on the mapping. "Subjective, individual meaning" seems to just refer to personal thoughts and interpretation. It's fine to have personal thoughts, but "the author's meaning" is what they ultimately attempted to make others think is the message within the work. So to make comparisons between properties of the author's meaning and personal "meanings" is comparing apples to oranges, no?