Here's why:
* The speaker's grief remains: The poem revolves around the speaker's overwhelming grief over the loss of his beloved Lenore. Throughout the poem, he seeks solace and answers from the raven, but the bird's constant repetition of "Nevermore" only amplifies his despair.
* The raven's message is ambiguous: The raven's pronouncements, while seemingly definitive, are open to interpretation. The speaker desperately tries to find meaning in the bird's responses, but ultimately he is left with more questions than answers.
* The speaker is left with no hope: The final lines of the poem leave the speaker in a state of utter hopelessness. He is trapped in his sorrow, with no escape in sight. The raven, a symbol of his despair, remains a constant reminder of his loss.
While the poem might be seen as having a dramatic climax with the arrival of the raven, the speaker's internal conflict – his grief and desperate search for meaning – remains unresolved. The final image of the speaker, "shadowed" by the raven and "weak and weary," suggests a continuing state of anguish.