I think this is a confusing essay, because in everyday speech "art" is employed to mean something very different from "an art" and we get lost in semantics. The continued references to obsolete definitions confuse things further.
In practice, the phrase "an art" is usually used in the same way as "an artform", as it is not meant to be taken literally; a commentator may say "there's a real art to mastering the offside trap" in football, but he does not mean that the defender should be put in a glass case in a contemporary art gallery.
The whole art/science classification of programming appears to me to be people defending their philosophy or encampment. If you're working in formal methods, you're likely to say "it's about the science", but if you're hacking the last cycle out of a console processor in the games industry you might say "wow, that was really clever, it's really an art this isn't it?"
I'd say both of these views are daft. "Science" is usually synonymous with Physics/Chemistry/Biology, which are inescapably different from programming or Computer Science. Similarly, fine arts is not isomorphic to programming.
What we usually do is much more like a craft. Sure, it has elements of engineering and maths, and in CS research we borrow some of the scientific method some of the time, but you could probably say the same about any craft, e.g. making jewellery, pottery, etc.
All crafts can strive for both beauty and utility, and can borrow from scientific methods and engineering when appropriate, but "pure" science or "pure" art they ain't. There's no ground truth in craft, and there's a strong degree of utility, which precludes it from being science or art respectively.
I've heard this discussion dozens of times. Always the mathematicians want CS to be a science, and the hackers want it to be an art or maybe engineering, but I think the argument is counter-productive. Programming is quite unique, but if you really want a relative description, it's kinda like a craft that uses certain maths and engineering in places.
I think dropping "science" from "Computer Science" would help immeasurably. Simply renaming a university department to "Computing" might stop students and staff worrying what they are.