For whatever reason, I would guess they think it is good. Galleries are probably more interested in emotionally grabbing pictures than (technically correct) "beautiful" pictures. I can tell you that I'd take that truck picture over a lot of the pictures I see other traditional photographers printing.
Originally Posted by Felinik
What I learned in school was that artistic beauty is a combination of skill and background. In other words, to really appreciate whether or not a work was beautiful you couldn't merely look at it, to really appreciate it you needed to understand its intention, history, creator, etc. And this is what has been already said - what is technically "bad" can be good if it fits with the artist's intention - and how can we know the artist's intention without knowing a little bit more about the piece?
My cop-out answer is that we are sick of technical pictures that can practically (I said practically) be taken with the click of a button on ever-improving digital cameras. We want pictures that break the rules and so when we find a cool picture that breaks the rules we want to believe it is intentional because we want it to be better. Which might be why I think the truck picture was taken by a photographer who knew his trade and not by a five-year old.