Brahms burned about half of his compositions, believing they didn't deserve to be seen, let alone performed or published. The pieces that survived in other copies have led musicologists to conclude that the work he burned was probably as good as that which he allowed to survive.
Eugene O'Neill specified he wanted
Long Day's Journey into Night to be published twenty-five years after his death, but his widow thought better and I'm glad she did. Consider the great productions we'd have missed -- and think of the catharsis which that play has afforded so many audiences. In one way, it's terribly depressing; in another, it offers intensities of honesty and compassion that can assuage a depressive's pain like medicine.
O'Neill tore that play out of himself in pieces and that's exactly why it has helped so many despairing people.
The artist isn't always the best judge of what should and shouldn't be seen. Negative vanity -- that distorting mirror which allows anything to appear misshapen -- can make objectivity impossible for anyone.