Different approaches. Poetry structure can be all over the place from almost non-existent to something like a sonnet. The power in poetry I think is trying to find surprising imagery to express the point, and that shift in perception is what this article is arguing for.

Is there value in free writing? Of course. I've done morning pages. I've also done free writing when struggling with problems in multiple realms (code and prose/novel writing). But sometimes it simply doesn't push you hard enough compared to the forced perception change.

You can certainly TRY to create that change in free writing, but then are you REALLY free writing, since you are limiting what you put on the page?