As others have mentioned, Bourdieu would like a word with him https://en.wikipedia.org/wiki/Distinction_(book) Graham seems to be conflating skill with taste. The artists he mentions are skilled at art and he states that he is not. Distinguishing between skilled and unskilled work may be "good taste" but what is considered good art is more than just skill.
While it is true that there are people who have a high degree of technical skill (or of talent) who have poor taste, which means that skill is not the direct cause of taste, it is an essential -- and significant element.
It's like assuming that practicing athletics does not make you better able to appreciate the achievements of other athletes.
Skill give both awareness and depth to your perception, and if you think neither of these attributes are applicable to determining quality, you lack the linguistic or cognitive ability to join the discussion.