> There's nothing we can say about a thing with "quality" we couldn't also say by tediously listing every single property it has. The only thing that only "quality" can add is information about what the speaker thinks is good.
In most fields (film, painting, music, etc), there are standards -- agreed upon to varying degrees, sometimes almost unanimously, sometimes with only a plurality -- based on objective or almost-objective criteria. In other words, there are "measurable" criteria that expert or even merely good practitioners can agree on. In these cases the word "quality" is often used as a shorthand for possessing these kinds of properties. In this sense, ascribing quality is functionally different from a mere opinion, linguistically and technically.
Of course, you can argue that all those experts have no priority over anyone else's opinion -- nevertheless, the usage distinction remains. In addition, I think that point of view is either trivially true (because sure, no we can't ask God to tell us who's right) or meaningless (because there are many differences between experts and non-experts, even if you have contempt for expertise).
In most fields (film, painting, music, etc), there are standards -- agreed upon to varying degrees, sometimes almost unanimously, sometimes with only a plurality -- based on objective or almost-objective criteria. In other words, there are "measurable" criteria that expert or even merely good practitioners can agree on. In these cases the word "quality" is often used as a shorthand for possessing these kinds of properties. In this sense, ascribing quality is functionally different from a mere opinion, linguistically and technically.
Of course, you can argue that all those experts have no priority over anyone else's opinion -- nevertheless, the usage distinction remains. In addition, I think that point of view is either trivially true (because sure, no we can't ask God to tell us who's right) or meaningless (because there are many differences between experts and non-experts, even if you have contempt for expertise).