Book banning

[Spongebob]

Yes, this is a good point, and tricky. 

There is a lot to consider when we want our literature to teach a moral lesson. A lot of people deny that literature can or should do this at all. All the "art for art's sake" people, from Oscar Wilde to Nabokov, denied that the arts can teach morality. If it tries to do so, it is propaganda, even if we agree with it. Or we could argue that the moral aspect comes only from whether the work increases or decreases the subtlety of one's thought, and that even the most obvious moral teaching (like "racism is bad") works against the morality of literature if it is expressed in a way which decreases the reader's personal experience.

This is why I'm skeptical about using books like this in a classroom, for a specific political purpose. It is very very easy for a student to read the lesson and agree, for the duration of the class, that racism is bad without gaining any increased insight into his or her own racism. I'm NOT saying this is true of To Kill a Mockingbird (I don't know that book well enough, and it would depend on how it was taught), but I think it is true of nearly all the easy moral lessons that appear in TV shows. In Star Trek, for example, we are repeatedly taught about the superior values of the brave and noble Earth people, who all share the values of liberal Californians. But I seriously doubt that these "lessons" do anything more than flatter the audience, making them proud to agree with the attractive actors, and comfortable in the notion that in the far future their own values will win the day. But no serious challenge is ever posed, and then most problems are solved in the end with a fist fight or phaser blast -- which in fact reinforces the common American idea that the Good Guy is always the one who makes the most successful use of violence. 

I'm tutoring a high school girl now, who's in the International Baccalaureate program here in my city. (I normally have a rule against teaching kids, but she's a bright girl.) The reading list for her English Lit class is like a list of socially woke propaganda, and virtually no discussion is made of any other literary quality. It's frustrating, because I agree with every single text that patriarchy is bad and micro-aggressions are evil, but since that is the only message included in the class I wonder about its quality. Like if the goal is really "teach them how to think, not what to think," then this class is a failure. 

But again, I don't know enough about what happens in most classrooms these days, so I'm not arguing on the subject of Harper Lee or use of her book at all.

Yes, there are certainly pitfalls to the practice of 1. teaching morals from fiction and 2. intentionally baking morals into art.  Yet both are time honored traditions, so not doing this would alter a course that we've been on for centuries, perhaps millennia.  The key to successfully practicing the second is deft.  Since you referenced the ham-fisted efforts of early Star Trek: TOS episodes, I'll point directly at "Let That Be Your Last Battlefield" as an example of poor quality, but I will reference one of the far more nuanced episodes of Star Trek: TNG, "The Crucible" as a much better example.  This story specifically asks us to closely examine what it is we call "intelligence" or "sentience" and to explain our definition of life and freedom and does so with exquisite skill.  In this episode, you realize what is happening but you don't care because you are caught up in the question and can actually see value in both arguments.

Regarding whether using fiction to teach morality "works", as in delivers a desired message to the student, I would argue that any reasonable means is fine since the end is learning what is socially acceptable.  I certainly prefer it to sermons, of which I listened to probably thousands as I grew up.  And sermons themselves often utilize stories to convey their message.  The Bible is full of allegory.  Weather a student accepts the message as valid and internalizes it is a completely different matter.  Different people respond to different stimuli.  Some people won't accept a message no matter how you deliver it.  Some won't accept any message at all while others are altogether too easy to shape.  That's why teaching itself is mostly art with a little science sprinkled in.  And as such, teachers use a variety of methods to convey a message.  In short, they use whatever works.

I've heard the cries of fanboys who hate stories that appeal to SJWs (as if that should be a pejorative thing), in particular in the comics world.  Some have sworn off the medium because of it, but those people are historically tone def.  Comics have essentially been doing this since there inception to varying degrees that change with eras.  During the CCA era they were essentially forced to do this to a ridiculous degree, but have since become far more adept at it.  One of my all time favorite story arcs was the Green Lantern/Green Arrow story "Snowbirds Don't Fly", 1971.  Again, the degree to which this sort of thing is palatable depends largely on the skill of the creators.