Are writers the best judge of their own works?

As writers we all like to think this book we are writing now will be our greatest - our major opus!  But at the end of our writing life which book or artistic creation I wonder will we  wish to be remembered by.

 In the 19th century Thomas Hardy wrote sensitive, deeply moving and memorable books on love, infidelity and betrayal, as well as the anguish and frustration suffered by labouring men with bright enquiring minds but without the financial independence to pursue the academic lives they craved.  Hardy's novels were ahead of his time, offending Victorian sensibilities and showing up the bigotry and hypocrisy of the age he lived in.  To my mind his novels were his best work and the world is far richer for such outstanding works of literature. But poetry was Hardy's first love - he was a poet by choice; a novelist by necessity - and it was for his verse that he wished to be revered and remembered.

Michael Farrell's masterpiece 'Thy Tears Might Cease' was published after his death only because in his lifetime he held on to it fearing it was not good enough for publication.  There is A.J. Cronin's best-selling  'Hatter's Castle' which the novelist's wife rescued from the bonfire and sent off to a publishing house on his behalf. But sadly not so fortunate was  John Kennedy Toole whose fine book 'Confederacy of Dunces' gained fame and recognition too late for its despairing author.

The acclaimed singer, Count John McCormack, set great store on his operatic arias and very little on his Irish ballads and yet it was those simple ballads so beautifully sung that were the most popular and best loved of all his works, not only in his lifetime but standing the test of time to the present day.

Does this mean that writers and artists are not the best judge of their own work or can it be in our continual quest for perfection we do not see or value what is already there?.