Why is this book considered iconic? Because it's the most life-changing experience a work can ever get. Why is that so?
Because it helps people having been sexually abused to get over it.
You definitely must read this book if you have any experience related to sexual abuse and are well aware of its consequences (whether you came through this problem yourself or not). You'll definitely like it-- and it's more than simply "like" it.
People disliking the book because of Holden's annoying character are missing the point. And I don't blame them, because they most certainly don't have the experience needed to get it.
The Catcher in the Rye is about a young student experiencing the direct consequences of sexual abuse. And the reason why the book is life-changing is because it teaches you that you're not the only one in this world to suffer and to hate the world, you're not the only one that don't ever want to hear about sex, and because it allows you to see YOURSELF with the needed detachment to see how pathetic you are and how worse you can become if you don't get over it.
The only way someone could ever come with a book this TRUE is to have come through this type of problem once. That's why... Salinger's death strongly moved me.
Hope I've been helpful to people not understanding why is the book so famous, and made some of you want to read it.