This avoids and doesn't answer the question: Which matters are matters of taste (preference) and which are not? Or perhaps it should be put this way: Which matters that seem to be matters of taste are susceptible to refined and critical judgment?
Is "The Asphalt Jungle" a better movie than "Jail Bait"?
Is a painting by Van Gogh a better painting than the typical drawing of a 3rd grader?
What criteria go into "better" in these contexts? Connoisseurs of film noir can understand the principles of beauty and art within drama and films, so that they can pass judgment critically and knowledgeably, and not merely vote for a favorite based on the idea that any vote counts as much as any other vote because there is no "truth" to be found in principles of aesthetics.
There is no denying that people have different tastes and express them in innumerable ways in their choices of how they spend their time, what movies they watch and a thousand other ways. Does this imply that there is no truth in principles of art or that it's futile to attempt to express such principles? The one thing doesn't follow necessarily from the other. Because people speculate in many ways, this doesn't imply that there are no useful principles of speculation. Because people comprehend physics in a multitude of flawed ways doesn't imply that there is not a set of physics principles that is best; and that conclusion holds even though we know that what is best changes over time as discoveries are made.