For many, reading is an escape. It's the chance to fall in love, have an adventure, defeat the forces of evil. But what happens when a book does none of those things? When characters don't grow, when resolution is not found, when there are no significant changes? When is your story...pointless?
Wish You Weren't Here
Many books contain action. Walking across the room is action. But what happens when the character gets to the other side? In books, it's not always the walking that makes the difference. It's what happens at the end.
And in some books, nothing happens. The character goes across the room and sits down. Unless something falls out of the sky, why bother taking me on that walk?
It's pointless when characters learn nothing from that walk, face no consequences and make no decisions. And when that walk doesn't even move the plot forward in some way, it doesn't belong in your book. Every single sentence, and I cannot stress this enough, ought to be achieving some purpose. It should give information, make something move, create a feeling, reveal a secret -- something. Even one pointless sentence can be the ruination of a book.
But entire books can be pointless, too. It's not enough for the character to simply have experiences. It's not enough to merely walk across a room. Something has to come of it. Storytelling isn't just about painting pictures or writing good action scenes or even crafting great dialogue.
Never, ever forget the basic rules of storytelling. In stories, there should always be a beginning, middle and an end. The character shouldn't be the same in the beginning and middle of the book. Something has changed them by now. A love is lost, a dream is dead, an outlook is different. By the end, the character has changed again. If I can read the first page and the last page of your book and not see these changes somehow, you have a problem.
If readers can't find that difference at the end of your book, some of them might feel that it's pointless and that their time has been wasted. You never, ever want a reader to feel this way. So sharpen up that story, and show me the change. The journey will be much more worthwhile if you can.