At the UW reading, someone from the audience asked me about the characters in poems. I don't feel I gave him a suitable answer to his query. For the life of me, I don't remember the exactly what his question was, but I do remember that it had to do with that juncture in the writing process when you know you need to stop. It blossomed into the "why poetry and why not short story" question.
Here's the thing about character in my poems . . . I never try to resolve their crisis. It would be a difficult thing to do, especially in a single poem. Also, I never feel it's my aim to attempt to resolve a character's crisis at any moment of the poem. Rather, I'm more interested in the context of the crisis and what that context implies about the world of the character.
The other thing about characters in my poems, if there's a 1st person narrator, that narrator is rarely the focus of the poem. Often, the 1st person narrator is describing someone else. I think this is mostly because I don't trust my characters to do an honest job of describing themselves.
Finally, I don't think I have the patience to sustain a scene as a writer, nor do I have the patience to meet the demands of the revision process in fiction. I'd spend far too much time editing one sentence. I use character in poems because 1) I like masks, 2) taking on another POV allows me to toy with perspective 3) both of those things allow me to lie far more than my Catholic guilt would normally allow.