I guess I think of poetry in three senses.
Poetry in the small sense, that is, received opinions on poetry held by, oh, the culture at large. "Oh, isn't that poetic!" "I was feeling upset, so I wrote some poetry and now I feel better." "I'm a poet and I don't even know it!" And so on, et cetera, und so weiter, kaj tiel plu.
Poetry in the middling sense, that is, poetry as the creations of a bunch of people and communities that think of themselves as creating poetry or working in poetic traditions. These creations are often called "poems". See this is slam poetry, that is post-avant poetry, this is a poem I wrote for my dog, this is a Norton anthology filled with poems.
Poetry in the large sense, that is, anything that is being read or understood as poetry, whether everyone would recognize it as poetry or not, whether it was created with the understanding of being poetry or not.
Hopefully this has clarified nothing. But I think that when I make big "poetry is X" statements (a bad habit) I sometimes would say something different if I were talking about a different sense of poetry.