I would certainly agree that its practice is an art, as follows.
Its products generate aesthetic pleasure in other practitioners and even in non-practitioners (like me) whose brains are similarly wired. So ordinary people who do not play musical instruments or sing and act can nonetheless be moved by witnessing an opera performance, in the same way that we experience pleasure in reading an annotated description of for example Bohr's stepwise thought process of inventing the first generation of quantum mechanics.
It is a teachable discipline, in which particularly gifted people can learn the tools of the trade and become active practitioners themselves- and even in those cases where the student does not become an active practitioner, the student learns nonetheless how the process works and gains an appreciation for not just the product but also the process. In this regard science is no different from oil painting, sculpture, poetry, dance, music or acting.
It is, however, far far easier to make a living through the practice of science than in the practice of the other arts described above, because the fruits of science are tangible objects (TV's, computers, cell phones, cars, airplanes, bridges) which serve useful functions instead of just providing aesthetic pleasure. This means ordinary people will pay money for those fruits without regard or understanding of the aesthetics behind them: people buy refrigerators every day but those same people do not commission operas, or write them.
This is why I stopped being an electric bassist in 1979 when my degree work was complete and went to work as an engineer in the inkjet field. But in all the years that followed, I continued to pull my paints and brushes out and dabble around, metaphorically speaking- that is, music became my hobby instead of my vocation.
And now that I have retired from the high-tech field and no longer work at it for a living, I still dabble in engineering as a hobby, when I am not dabbling in bass playing as a hobby. The similarities are manifest, and the most fun happens when I blend the hobbies together. Illustrative examples are available on my website, www.nielsenkillowatt.com.