For a lot of people, Superman is and has always been America's hero. He stands for what we believe is the best within us: limitless strength tempered by compassion, that can bear adversity and emerge stronger on the other side. He stands for what we all feel we would like to be able to stand for, when standing is hardest.
The point of mythology or myth is to point to the horizon and to point back to ourselves: This is who we are; this is where we came from; and this is where we're going. And a lot of Western society over the last hundred years - the last 50 years really - has lost that. We have become rather aimless and wandering.
For me, growing up in a ridiculously poor family living in dead-end neighborhoods, Superman was a deeply personal icon, one that said you can do anything if you put your mind to it. What he stood for formed the core of who I wanted to be as I grew up, and informed how I view the world and my responsibilities to other people.