Talking about the interest in saying something abnormal (and preferably profound) is another way of referring to creativity, since creativity includes originality, the production of something new.
I agree, though, that creativity isn't an end in itself. The point of creative uses of language is to show what isn't normally communicated. We want to challenge our viewpoints, to look at the world in a new way, and to hint at profound truths that might be hiding in plain sight.
Judging the quotation from my poem in that way isn't fair, mind you, since the point of the poem emerges from the whole of it, whereas I quoted only a part. Still, a metaphorical way of talking about the brain can make us think of the brain differently. The idea of being a "castled conspirator" might suggest the brain is cornered, trapped in the skull, potentially alienated, or that the brain sends out its pawns (its body) to dominate the board, as an overcompensation for its vulnerability. None of that is as easily connoted by the simple word "brain."
Gorman's poem was plain spoken, so I'm not sure what you mean when you say she "shared feelings in a way that can't be done by simply saying it plainly." That's my point. She did speak plainly, which makes her "poem" prose.
We have to distinguish means and ends. Gorman's goal might have been to say something new and profound, but her means were just the ordinary uses of language, with some gestures towards poetry (the rhythm and rhymes). Thus, her intentions might have been poetic, but what she actually said or wrote wasn't so.
This is like saying the infamous movie "Planet 9 from Outer Space" was a masterpiece of cinema, because Ed Wood's intentions were noble. Wood wanted to produce a great movie, yet if only doing so were as easy as having the right intentions. No, you also need the skills to make it happen so the finished work speaks for itself. We're not inside Gorman's head. All we have is her "poem" which isn't so creative or original in its use of language, as a matter of objective fact.