Correct.
Anons who express this view are always the most stubborn, shallow, art-retarded, muh-materialist-science-atheism, niggers on the planet so I'm hesitant to actually get into a serious discussion about this for the millionth time but, briefly, no, there are no "objectively measurable aesthetic qualities". This is not the same as saying that there's no objective truth as to whether a piece of art is good or bad. Just that, whether or not value claims about aesthetics (i.e. "this is good", "this is bad") have objective truth values (I think they do personally), there are no empirical criteria (typically what someone means when they make reference to "objectively measurable…qualities") by which the truth value of such claims can be ascertained.
And no, "realism" in visual art or "complexity"/"mastery"/"difficulty" etc., in arts in which "realism" doesn't make sense, are not objective measures of quality. There's a huge amount of absolutely debased garbage visual art done at an extremely high level of realism and technical mastery, as well as debased garbage music that's extremely complex and technically difficult. There's also a huge amount of emotionally powerful visual art and music that's technically simple and/or not particularly visually realistic.
As notes, the quality of art has to do with what's expressed and how effectively it's expressed, or put another way, what's evoked and how strongly it's evoked.
Good art evokes things that are good and/or evokes in such a way that the evocation itself is good. The good itself, while objectively good, cannot be objectively measured or expressed by any conceptually, linguistically, empirically sound means, which is why we have fucking ART in the first place.
