To all defending Modern Art: Please point to at least one item available online which exemplifies that which you think I'm ignoring or missing.

Funny -- I didn't actually read the post as an attack on Modern Art. The point seemed to be that, appearances to the contrary, Modern Artists are in fact trying to hit a narrow target, albeit not the one you might at first think. It is presumably this attempted optimization that makes Modern Art (to the extent such a thing does in fact exist) a worthwhile or interesting activity to those who practice it.