It is good advice for any writer to look for patterns in reviews.  If a number of readers all complain about the same matter, even if their interpretation is incorrect, it means the writer either did not explain the issue properly, or failed to reach the correct audience.
At the same time, a reader should comprehend the subject or genre enough that axiomatic issues don't need to be explained because they are axiomatic.
To see an example of this, we need look no further than modern "liberal" science fiction readers and Heinlein's novel, "Friday."
I first read this in high school, and understood it on several levels.  But, as of the mid 1990s, I've heard repeated complaints, most of them around the assumption, "No woman falls in love with her rapist."
Well, first of all, women do that all the time, and with non-sexual abusers, too. There are a variety of psychological discussions as to why this is, but they're outside of my field and beyond the scope of this post.
The important point, and Heinlein was not at all subtle about it, is that Friday is not human, she is an alien.
She is an Artificial Person, required in every society in her world to carry ID stating so, and discriminated against in levels from being forbidden to vote or own property, all the way to slavery or sanctioned extermination.  Due to her job as a clandestine agent, she has fake ID that says she's human, and she's well aware of the privilege she holds over others of her kind, and is ashamed and guilty about it.
She is so very aware of her non-human, unperson, unclean status that even the act of being raped and tortured doesn't bother her emotionally.  It's just a thing, like getting wet in the rain or having debris fall on you. Artificial entities that are not people don't feel emotion, or so she's had beaten into her her entire life.
Except of course, at another level, she actually is human, and is grasping at personality and self worth.
It's a constant matter of discussion for the character. "How do you feel about Artificial Persons?" She could as well, within the last century, asked about gays, Jews, blacks, and the question would be as relevant.  She asks this because she looks like a "normal" human being, and is, as are the others, even when a society doesn't recognize that.
Her boss/father figure constantly reassures her she is normal and human.  She's genetically engineered to the point where she is smarter, faster, stronger, fitter and more durable than almost anyone around her, but this vulnerability is the vulnerability of spirit, and no amount of labwork can fix or prevent that.
Further, the rapist she eventually falls in love with was himself both an Artificial Person, and a slave, being ordered to perform the task. It's made very clear he isn't happy with it, and would like to treat her decently, but is forbidden the opportunity.  He also is not "human" for purposes of the society.
Nor was Heinlein particularly subtle about it. Every chapter has an interaction with a family, partner, friend, associate on how frustrated she is at not being human, not being accepted, considered a thing, only of worth as a machine to be used and discarded.
The failure of readership is that despite the very obvious presentation of a character as an outsider to the society, not only unsuited to it, but ostracized by it, all those particular readers see is "female body, ergo female human."
Exactly the same issue so many of them claim to care about and rail against in other contexts.
They are literally so privileged they are unable to grasp the point of view of the underclass even exists, much less what it is.
This supports an hypothesis of mine that most such "social justice" types are themselves exceptionally shallow, narrow-minded bigots.  When something even more blatant than "Friday" comes along, and they are forced to be aware of their own human failings, they over-react, as does the reformed alcoholic or druggie who suddenly "Finds God" and obsesses over religion (versus faith or piety) to the point where it's apparent it's merely a substitute addiction.
Once aware of their own failings, their form of denial is to project their shortcomings onto all "normal" people, who obviously feel as they do, about those "non-normal" people they suddenly realize were in fact human beings all along.
If anyone dares to say, "Yes, I knew about this, and your sudden obsession is disturbing," they still struggle with their own internal ignorance, reluctant to accept their error, and can only assume their antagonist must not actually grasp the wrongness.
When I began writing this, my thought was, "These people shouldn't read science fiction. They're obviously incapable of comprehending it."
But I think instead, they should read science fiction, rather than the crap they have replaced it with, where every culture and cast is stratified into the "correct" ratio and recognition.
Because that type of society is exactly the problem, and they still don't get it.