post-post-modernist? oh gosh please don't tell me this is a buzz word lately.
well, definitions aside, are you just basically looking for contemporary art writers who leave you with a warm fuzzy feeling inside?
I can't think of many off the top of my head, but if you haven't already then u should read Homi K Bhaba, the Location of Culture.
If that is too heavy, then maybe see if Bob Ross wrote anything about happy tree, clouds etc.
Also, going back into the 20th c. I know Donald Judd was not a fan of post-modernism, and if you can stomach it, try reading Ayn Rand's art theory. I'd love to have those 4 people at a party, give them a bunch of whiskey and see what happens.