The Complete Stories and Poems question

One reason is we are of a generation requiring instant gratification--we have not learned to savor, to ruminate, to actively think about what we feed into our minds, and therefore, cannot appreciate the nuances of poetry.

1. Too expensive, modern poetry is 90% a wasted of time

2. Hum, see above?

3. Annabel Lee, So we no more go a roving, She walks in Beauty, I wandered lonely as a cloud, The Poison Tree, Tiger Tiger, Funeral blues... and a lot more

Well, poetry is expensive, but there are really cool things being done right now, for example in Alt-Lit.
People never has bought a lot of poetry books. At least not for the last hundred years or so.
And, concerning the third question, my favorite poems are all by Bukowski.

I have favorite poets: Mary Oliver, Christina Rossetti.

I don't buy poetry often, but I love having my absolute favorites right at hand. The rest I sample online for free. The same for fiction and non-fiction. Every dollar has to work extra hard these days!
I think I never learned to like poetry much in school, for one thing. Few people appreciate a good turn of phrase, a well considered thought, in conversation. Instead we have commercial jingles and sound bites.
Too much of the more modern stuff is like modern art: it does not resonate (for me) with the timeless themes of humanity.

I do not buy poetry very often because I am not a poetry fan in general. However, I have read a few great books over the years and it all depends on what a person likes.

New Love Poems by Terry Benczik was very enjoyable and is a little know author, which is a shame.

As a poet/author myself. I buy poetry because I want to learn and grow as a writer. I can see why most people find modern poetry cringe-worthy especially when it's become more about whining social justice than actual thought-provoking work.