I can see why some people find the centered subject boring...
That's the little thing i keep, at the base of super different art with different color schemes, composition, moods etc... to have something recurrent, cause i want something recurrent in my art.
I think it works really well in some pieces, just not in all of them. I also think it somewhat limits your potential for expression. Some of my favorite works of yours are not strictly subject-center, for instance the 30 Years of Mario or the Secret of Mana.
I appreciate your explanation though. It was very thoughtful.
Keep up the great work.