It's interesting that your article is stuck on the confusing modern definition of art. Considering the fact that creativity takes off within limitations, it makes sense that the lack of limitations constitutes the promotion of mediocrity.
However, originality is not the focus of art. The reactions of the viewer is also not essential.
Art is the act of creation, not limited to a medium, but expressed through one. The goal of art and the artist, is self expression; the processing of life experiences into concentrated forms that allow a viewer to go through an emotionally charged experience which 'might' be similar as the artist.
Last point: the greatest disservice that ever happened to art was the formulation of Post Modernism. Everything is acceptable, nothing is wrong, there is no right way to do things, no tradition to grow from and nothing to rebel against. The artist is the agitator. if there's nothing to push against, then mediocrity is all we have, which leads to decadence and eventually artistic dark ages.