My primary beef with poetry is that it's the most self-referential of all writing forms. Practitioners of poetry judge it by a different set of standards than avid readers and avid readers by a different standard than casual readers. Ask a man on the street what a poem is and he'll say "something that rhymes." Ask a poet if their stuff rhymes and they'll look as if you just asked them if they rape cats. I have never before experienced such literary scorn as when I told an English teacher my favorite poet was Kipling. Meanwhile, stand at a bus stop and ask people who their favorite poet is. You'll generate a lot of blank stares. If you're in, liking someone with commercial success makes you a peon which means if you're out, you're never making it in.
Prose is anything that isn't poetry. Poetry is everything else. Any category that covers Basho to Coleridge is going to have something to piss off every human that ever walked the earth, it'll just be all different shit... and poets tend to explore the corners where normals never tread. The end result is that if you find something you like, you're wrong because it sucks but if you ask for something you should like, it will suck.
I had an author tell me once that the best sentence ever written was
so much depends
a red wheel
glazed with rain
beside the white
And really? Fuck off. If an English teacher is gonna mark me down for starting a sentence with "so much" but then bukkake the fuck out of William Carlos Williams for doing the same, you are effectively telling me that poetry is poetry because you say it is, not me.