What is the subject matter? That's a matter of Creative Problem Solving on the part of the Artist:
Does poetry have to be emotionally rooted? No! Does it work really well for emotional release? **** yeah! Can it be an enriching endevour into Logic and Philosophy? Of course! Does that get old? .. I plead the Fifth.
I suppose it depends on who you ask.
Logical, left-brained, analytical mindedness is just as much a part of the coin of Creativity as the Mythic mindedness of the right-brain.
The two must harmonize in some way for one to be made of anything.