What we call "folk music" is not merely confined to its aesthetic categorization, in stereotype or the charts of marketing. Louis Armstrong: "All music is folk music. I ain't never heard no horse sing a song.” Bob Dylan is arguably the most important and defining figure of this art form from the entirety of the past century. He has always resented and eschewed his "spokesman of a generation" description, but regardless, he has expressed and portrayed civil strifes and emotional disillusionments for decades. Though from many occassions, he is what I would be inclined to describe as resisting against the absurdity of fame. With such a deep resentment of his impersonal idolization, he quite harshly insulted the American folk revival establshment, and releases an album such as Nashville City Skyline, during the most revolt and indginancy in 1968. Whether or not regarding his musicianship, which in its own accord in the height of its melody and performance equally as great, his lyrics easily stand by themselves, and are completely superior to plenty of popular doggerel that passes itself for poetry or creative writing generally. On the value of The Freewheelin' Bob Dylan alone in my view, yes, he deserves the Nobel Prize.
As noted by "Zook", there are multitude who also have not:
Gordon Ball - Dylan and the Nobel