Poets should be noble creatures of intuition, not car mechanics trading greasy-fisted blows over how to rebuild an engine. Anyone who finds the poet's obsession with prosody mysterious should listen to opera singers talk about techniques of vocal production. These conversations, too, are remarkable for their passionate concern with detail. Every detail of technique may open or close some expressive possibility. Superb technique may not create a great singer, but one cannot sustain a career without it, and bad technique can incontestably ruin a voice.
Words are the poet's only material, and prosody determines how they are arranged into poems.