/lit/ - Literature

Being a total novice to poetry outside of a few poems I've written over the past year, I took a cursory glance at some of the best regarded poets of the past century, namely Roethke, Plath and Doolittle. What confused me most is that compared to the poets I'm familiar with (such as Keats, Poe and Milton), modern poetry features no meter and rhyming seems verboten?
Reading some of Roethke I thought to myself, what is this but regular prose with more frequent commas and semicolons calling itself poetry. Sure there are messages being conveyed through the verse, but I believe poetry is at its best when there's at least a meter to follow. Poetry surely should come with a natural flow of rhythym instead of being laid out in spasmodic sentences.