I heard Billy Collins read the other night. The professor I went with took this note on something he said.
"One statement he made rings true: poets write for other poets and do so by displaying their love of poetry--the sculpted word--because no one is so foolish as to think another person (other than, perhaps, Mom) cares about his inner life. Readers are too wrapped up in their own to care about another unless that other comes bearing gifts of beautiful craft."
I'm not sure if Billy said that poets write only for other poets, but that when they write they show respect for their reader and worthiness to be read by writing in a beautiful way. It's the beauty, not the poet's inner life, that is the draw to any reader.