With the recent death by hanging of Nicholas Hughes, son of Sylvia Plath, the New York Times asks “Why the Plath Legacy Lives”? Joyce Carol Oates notes,
The suicide of Sylvia Plath was and is obviously of enormous cultural significance because Plath was a brilliant poet—at the time of her death she was already considered a very important poet and since her death, her reputation has risen continuously while others who were her gifted contemporaries—Anne Sexton, John Berryman, even the much-acclaimed Robert Lowell—appear to have faded.
JCO has written extensively on Plath, most notably in “The Death Throes of Romanticism: The Poetry of Sylvia Plath:”
… the cult of Plath insists she is a saintly martyr, but of course she is something less dramatic than this, but more valuable. The “I” of the poems is an artful construction, a tragic figure whose tragedy is classical, the result of a limited vision that believed itself the mirror held up to nature—as in the poem “Mirror,” the eye of a little god who imagines itself without preconceptions, “unmisted by love or dislike.” This is the audacious hubris of tragedy, the inevitable reality-challenging statement of the participant in a dramatic action he does not know is “tragic.” He dies, and only we can see the purpose of his death—to illustrate the error of a personality who believed itself godlike.
All of the Plath writings are collected in JCO on Sylvia Plath.
I'm a Reference Librarian at the University of San Francisco's Gleeson Library, and I run the Joyce Carol Oates web site, Celestial Timepiece.