Finally: a written confirmation of what I know but have been unable to express: page 42 in The Mind of the Maker by Dorothy L. Sayers:
To write the poem … is an act of love towards the poet’s own imaginative art and towards his fellow-beings. It is a social act; but the poet is, first and foremost, his own society and would be none the less a poet if the means of material expression were refused by him or denied him.
We like precise definitions, concrete reality. It’s easier to deny a label to someone unpublished; it makes us feel better, like we can use such rules to narrow reality and make it easier to deal with, but how many negatives are needed to make such a strategy work: if the poet does not connect with the right publisher, if an editor changes his work so it loses its essential essence, if the marketing department fails to effectively get the book sold, if no one reviews it, if the poem takes shape when no means of recording it are to hand, if war prevents the manuscript from getting through?