Bowie disregarded everything but himself. It's not difficult to disregard this outlook on the world, because it is not even an outlook on the world, it's more akin to a denial of the world.

"The man who destroys himself creates the universe. To the humble man, and to the humble man alone, the sun is really a sun; to the humble man, and to the humble man alone, the sea is really a sea. When he looks at all the faces in the street, he does not only realize that men are alive, he realizes with a dramatic pleasure that they are not dead."

Yet, Bowie could not ever quite make a convincing case that he believed other people are not dead, or at least that their existence was anything more significant than their non-existence because for him, all significance came from him and him alone.

Well, then he gave up cocaine and had lots of happy years of further creativity. I think you're mistaking the Thin White Duke for the guy who survived portraying the Thin White Duke. I guess he's throwing darts in haters' eyes, too :)