The real story is that modern technology and social media make us a much more oral society than we once were. Naturally poetry will be delivered more through the ear than through the eye—just as it was for most of human history, and still is in most of the world’s 6,000 languages, only about a hundred of which are written in any real way.
And it doesn’t help that modern poetry is often intentionally something other than comfort food. Without rhyme or regular meter, embracing ambiguity and often deeply individualistic, much of it almost willfully transcends the bounds of popular taste. Lamenting that America doesn’t cherish poetry like this is like wondering why Milton Babbitt, Thomas Pynchon and Ornette Coleman aren’t common coin.