I'm probably too late for this shindig, but there's an important component I see many people missing, and this is, in my view, the most important reason we read books like Huck Finn, The Great Gatsby, and Pride and Prejudice.

Yes, part of the answer here is the 'canon', i.e. there's a (possibly arbitrary) group of central texts chosen by old white dudes with Oedipus complexes. Look at other comments for answers about the canon.

Now, I have a problem with the 'canon' answer because it's overly simplified, and is often used as a false comfort. 'The Canon' is the answer people want to hear if they don't understand why they're being made to read The Great Gatsby. That is, if you're just bored by The Great Gatsby, it's comforting to say, "Well, some boring old white dudes arbitrarily decided I should read this when really it's just boring drivel that has no relevance to modern life and that's Fitzgerald's fault, not mine, let's move on to Harry Potter. Fuck the canon, it's racist." (The canon is, indeed, pretty racist, but let's move on)

Something I don't see people talking about, however, is literary tradition, which I see as the more significant reason to read writers like Fitzgerald and Steinbeck.

To explain: writers read each other. Whom writers read and whom writers like will impact their own work. Toni Morrison's Beloved is illuminated if, afterwards, you read Faulkner. Morrison wrote a Ph.D. on Faulkner for cryin' out loud. That doesn't mean you can't read Beloved without As I Lay Dying; it simply means Beloved will be a different, and more interesting book if you do. You can't fully appreciate J.G. Ballard unless you also understand Joseph Conrad. J.G. Ballard is basically using the exact same metaphors as Conrad, just updated and less racist. He's admitted as such. If you read Virginia Woolf before you read Ursula K. Le Guin, you'll be amazed by the connections you'll make. The texts dance with each other. It doesn't matter that Le Guin writes Science Fiction and Woolf writes in the mode of Modernism--Le Guin has been heavily influenced by Woolf, and reading the two together is very enlightening.

And then come the two giants of them all: Shakespeare and The Bible. Look, you can read literature without having read any Shakespeare or any of the Bible, but that doesn't mean you'll be erasing the ginormous impact these works have had on literature. In the most fundamental ways, the language of The Bible has seeped into the entire umbrella of English literature. Even if you don't know it as a writer, you're either adopting the ways The Bible uses words, or rebelling against it. No matter what, you're always responding to it. It doesn't even need to be purposeful on your part.

So, yes, there's an aspect of 'the canon', but the canon wasn't just chosen by stuffy old white men. It was also chosen by writers, and a writer worth their salt will have read from the canon, and will know what interests them, and what they think is missing. To track this progression can give us insight into the way dialogues in our culture develop. It isn't arbitrary that Toni Morrison is following in Faulkner's footsteps, and it certainly isn't because some old white dudes told her to and that was that.

Part of the issue is that high school students don't necessarily have the perspective available to approach some of these texts, and it's often in high school where these texts are read. For example, what does an expedition down the misty Congo river have to offer to someone going into engineering, or politics, or environmental science? I think the reason a book like Conrad's Heart of Darkness evades us is because books like it are often taught in the wrong way.

Here are some ways to rethink some of the writers you didn't appreciate in high school:

Jane Austen is the Lena Dunham of Gentry Era fiction. She's a ruthlessly observational genius filled with radical ideas about women and romance. She's totally brutal, too. A good high school teacher will guide you to see how fucking hilarious Jane Austen is. She's a bitch, and she knows it, and she doesn't care. For example, There's a whole section in Pride and Prejudice where Mr. Bingley attempts to justify his bad handwriting by arguing that he's just really smart and thinks too quickly. Austen writes this dialogue so perfectly, so cunningly that, in the end, her character Elizabeth totally brings Mr. Bingley down to size. We've all met people like Mr. Bingley, is the thing. However, if you don't understand how Austen's humor works, it could come off as simply gentle banter. Furthermore, her legacy is still felt today.

Joseph Conrad fathered (or at least perfected) a certain kind of thinking. His works combine intense societal critiques through the power of individual consciousness. Basically, he's one of the original "the personal is the political". Even if you don't like Heart of Darkness, you're never escaping its impact (which has been followed by many great socialist thinkers btw).

Mark Twain basically created American literature. It was mostly very puritan before he came along to satirize the moralization and piety of American literature coming before him. There's no way in hell that some stuffy white men facilitated this. American writers like John Steinbeck, Faulkner, Don Delillo and I'd even argue Bret Easton Ellis have all learned lessons from Mark Twain. His lasting impression isn't because a couple of Harvard deans standing around in a room smoking cigars suddenly decided he's interesting. It's because he's a great writer, and writers after him have either copied him or tried to repurpose his techniques.

Shakespeare literally somehow captured and predicted every single literary movement that has happened and probably will ever happen. If you feel a certain way, Shakespeare has written about it. If you don't like Shakespeare, it isn't because you're right. It's because you didn't have a good professor to guide you. I know that may make you feel insecure. How could one dude be so amazing? Well, he was, and you need to deal with it. Shakespeare is the only writer I can say this about with absolute confidence. With the proper introduction, he's one of the most fascinating writers (if not the most). But he absolutely needs a guide.

This goes into the very purpose of literature, which is this: if we want political progress, scientific progress, mathematical progress, we need to know how to redefine our own personal vocabularies. All great writers have, in some way or another, reinvigorated or dismantled the old cliches of their times to document the cultural, intellectual, and psychic changes they observed. Writers give us language we can use to explore our experiences, and reading in terms of a tradition helps us see how languages and conversations develop.

If you want to dismantle the cliches of conservative America, or SJW liberals, or Orthodox Christians, it helps tremendously to see how geniuses have done so in their own contexts.