What does it say? What does it mean? These are pertinent questions an English student is required to ask. Constantly! I don't think it's necessarily as subjective as most people think, at least not the first question. The second, most definitely, depends on the audience reading the work.
I think the answer, for me, is that it means whatever you need it to mean. Not necessarily what you want it to mean, but what you need it to mean. I think people consider systems of belief and personal interpretation as a "desire" far too often. People don't believe in certain religions or principles because they want too, they believe these things because they need to. Because psychologically they are leaning towards that belief, they need it. They need to believe there is a god, or they fall apart mentally. They need to interpret a poem a certain way because it makes them feel better (or worse).
Our needs change, depending on how we grow, and the context of our lives. I'm not trying to remove personal responsibility from the equation of life and say that people simply do what they must, when they must, and that these compulsions are beyond their control. I'm simply saying that mood, mindset, experiences, insecurities and fantasies have a lot to do with how we interpret the world around us, and thus, how we interpret art and literature.
It's like how those songs about lost love on the radio are annoying when we're comfortably single, unnerving when we're in a relationship, and incredibly sympathetic and meaningful when we've recently lost a love.
When I read something, I need it to mean something inspiring. I need to take something away from that piece of work that makes me hopeful and confident. I need representations of things I'm starved for, like female solidarity, mankind overcoming adversity, people learning empathy, people becoming better people, and much more. Sometimes I even like stories that hint there IS a force greater than ourselves in the universe, and that it IS a beautiful, sympathetic, comprehending force.
Why are people so ready to embrace nihilism and darkness, labeling it (very unfairly) as "realism"? Why, when the opposite is just as plausible? It is just as likely that aliens will come down from the sky in 2012 to destroy us as it is that they will come to share with us images and tales of resplendent cosmic beauty, and to help us find our path towards transcendence. It's just as likely they'll be hideous to behold as they will be beautiful.
Since both are equally likely, we do have a choice in believing either potential "reality". Depending on who we are, and where we are, we may feel a need to choose one over the other.
Personally, I need to believe in hope, in any form. I need to believe we can and will traverse the empty spaces and create bastions of color and beauty. I need to believe that we will continue to grow in a positive direction. I need to believe in the innermost loveliness of humankind. Because it is there, right next to the darkness, just as easily recognized, and just as easily nurtured.
I need to believe that "peace" is a much more complicated word than people give it credit for. In my mind, it is simply the absence of violence and horror generated by humanity. There may be plenty of horrible things in the cosmos waiting for us. We can meet them and change them, or we can become them.
What do you need?