I want to stress that while I agree with you in principle, the counterpoint has merit as well.
Leaving aside a Descartes-style descent into solipsism, there's an understanding that qualitative values can be generally agreed upon (including the related terms and definitions, at least to a certain degree) by most people, and thusly compared. That's orthogonal to the issue of degustabus non est disputandum, not a rejection of it. Likewise, the correlation between the popularization of creativity (particularly within a capitalist context) and the degradation of quality is just that: a correlation. One doesn't necessarily have to cause the other, even if we still generally agree that there's a relationship involved.