Why would a poet use no capitalization or punctuation?
This is a bit of a subjective question, but let me throw in my two cents.
I feel like the lack of capitalization or punctuation could create a mood of carelessness, softness, or quiet. Like, my use of capitalization/punctuation in this answer I'm writing right now is me trying to create a mood/tone of academia, something to help you understand. but if i wrote like this and didn't use either of those things i could be trying to create a tone of not caring or unprofessionalism or maybe even the voice im using is quiet or younger.
Does that make sense? It's to contribute to the tone, to create a mood for the poem.