"Truthfully, art is not so subjective, except for "modern art," which is not what Kincaid does. Realism is very much a craft which has actual standards.
IMO Kincaid has ability as a craftsman, but my feeling is that his stuff is not straightforward or honest. This seems to be born out by various news stories and anecdotes about him."
Disagree with your note on the definition of subjective. Art is indeed quite subjective unless you show how standards are quantitated, which of course they can't be. Who set the standards and how did they arrive at the objective standards for art? I am open if I have missed something.
Well, I'll at least give you my take on it.
First, there is some truth to the idea that beauty is in the eye of the beholder, though that is really just another way of saying that we all have different preferences. This applies to not just painting, but to all art, music, poetry, prose, theater, etc. But it's plain enough that there are standards for those art forms that transcend personal preferences; there is good music and bad, good writing and bad, good acting and bad. You might prefer a paperback romance to, say, Huckleberry Finn, but you wouldn't think they are equal.
It seems only with "fine art" painting that the idea has taken root that it is all equal and not subject to objective standards.
I think I am right in saying that this idea dates strictly from the 20th century, especially the latter half. It's how stuff like Christ in urine (or whatever that was) gets justified as "art," for instance.
In any case, here are the five recognized (not by me, but by all artists who practice realism) quantifiers for judging the craftsmanship in realism in painting: skill in drawing, treatment of value (Kincaid's light), use of color, handling of edges, effectiveness in composition (referred to by commercial men as "layout").
FWIW, while I don't think Kincaid's work is great, it is not done without skill...I do find an insincerity and cynicism in it that is a real turnoff. It's like presenting a dish of icing and calling it a cake. Tastes sweet at first, but then you gag.