Writes the poet/critic Adam Kirsch (in the NYT). (Here's Kirsch enthusing over Philip Roth, who is, I suspect, in Adam Kirsch's basket of insulteds.)
Kirsch doesn't read Dylan's silence as a response to what Kirsch reads as an insult to to all the great American novelists and poets.
No one knows what he intends — Mr. Dylan has always been hard to interpret, both as a person and as a lyricist...Don't criticize what you can’t understand...
So Kirsch goes back to Jean-Paul Sartre who refused the Nobel Prize for Literature and, unlike Bob, explained himself (at length, here). And beyond that, Kirsch finds explanation in Sartre's "Being and Nothingness," which talks about "bad faith... the opposite of authenticity":
Bad faith [is] possible because a human being cannot simply be what he or she is... [B]ecause we are free, we must “make ourselves what we are.” In a famous passage, Sartre uses as an example a cafe waiter who performs every part of his job a little too correctly, eagerly, unctuously. He is a waiter playing the role of waiter. But this “being what one is not” is an abdication of freedom; it involves turning oneself into an object, a role, meant for other people. To remain free, to act in good faith, is to remain the undefined, free, protean creatures we actually are, even if this is an anxious way to live.And I answer them most mysteriously/“Are birds free from the chains of the skyway?”
ADDED: From Bob Dylan's great book "Chronicles: Volume One," here's something that cuts the other way from Kirsch's idea that Bob is about keeping himself for himself and not wanting to be the thing that is meant for other people. Page 16:
I could never sit in a room and just play all by myself. I needed to play for people and all the time. You can say I practiced in public and my whole life was becoming what I practiced.