There's an interesting piece in an old issue of The Boston Review tracing what happened to Richard Yates' reputation. Revolutionary Road is one of those books I've always heard great things about and meant to read but is so far down the list that in reality I'm unlikely to ever crack the covers. While this piece doesn't quite change that it does fit in with things like Kapsis' Hitchcock: The Making of a Reputation and Rodden's George Orwell: The Politics of Literary Reputation. I vaguely remember similar books, maybe one about Defoe, but there are numerous other examples of revived reputation (Donne, Bach, Melville, Faulkner) and even more of declining ones (though the examples there by their very nature tend to be more obscure - does anybody read St-John Perse anymore? Marquand?).
This is a tangled nexus of commerce, taste and lately academia though the artists aren't completely blameless. After watching Match Point a friend and I wondered how somebody can completely lose their way - Allen's last decent film was 1999's Sweet and Lowdown and his last better-than-decent was 1992's Husbands and Wives and the pickings are slim even before that. Had we over-rated Allen and he was never really that good? Had he run out of films he really wanted to make but continued anyway? Rock music is filled of course with people who peak early but it's a form dominated by what can be called inspiration; it's not designed for long exploration unlike jazz where even though musicians can audibly lose their chops as they age, they can also improve their music.
Not sure that this ties together in any way but....