Neil Gaiman and Adam Rogers write in Wired on The Myth of Superman
Superman is different because he doesn’t really belong to the writers who’ve created his adventures over the last 68-plus years. He has evolved into a folk hero, a fable, and the public feels like it has a stake in who Superman “really” is. Schwartz quit writing Superman because his bosses were telling him to put in things that he thought were out of character. That was admirable, but really, the specific stories we tell about Superman – the what-happened and what-he-did – don’t matter that much. Superman transcends plot. We retell his tales because we wish he were here, real, to keep us safe.