Are the "Great Works" of Literature Obsolete?

This post is inspired by my recent accomplishment: reading Catcher in the Rye. I like classical books as much as the next person, which is to say I mostly just like the idea of reading them and then impressing people with how well read I am.

The thing that got to me about Catcher in the Rye is that it wasn't really about anything. When trying to explain it to my boyfriend here's what I had to say: "Um...it's about a guy who gets kicked out of boarding school and he basically hates everything. He doesn't want to go home to his parents yet so he stays in a hotel and gets beat up by a pimp. Oh, but then he sneaks into his own house to say hi to his little sister and then later he tells her he's going to run away. But then he doesn't."

Ok, maybe I didn't do it justice, but can anyone tell me how to better explain it? I get that the kid didn't know what he wanted to do with his life and didn't see the point in going to school, those surly teenagers... But seriously, are these books actually doing today's youth any good? Is the reason we have them read this stuff in school to get the message? Or to learn how to expertly use spark notes to make it seem like they actually read the book?

Compare Catcher in the Rye to basically anything written by John Greene. I don't necessarily think John Greene is an incredible author but I've read a few of his books and they strike the same societal chord that, I believe, Catcher in the Rye was meant to strike. Teens going through a range of existential crises, trying to figure out what their purpose is. That about sum it up? 

So my question is, should the great works of literature still be used in the every day classroom, or have they become culturally obsolete? I don't know who determines what books are important for kids in school to read, but shouldn't they be reading pieces they can relate to? Is it so important for these kids to be able to decipher Shakespeare or understand the time and culture of Catcher in the Rye? 

Why not push new books with similar messages that may be of more interest to students and foster an overall greater interest in reading? Is there no other love story than Romeo and Juliet? Isn't it just as important, if not more so, to study literature from the past thirty years? Teach students about the issues we were just facing, are facing now, and will be facing. Leave the centuries old plays for some light reading when they're older and it won't completely deter them from the written word...