Does this variation in opinions of the utility a film provides mean or imply that we can say nothing factual about the content, quality, nature, impact and many other qualities of films?
Could we not make a list of qualities and say something objective about them and find wide agreement? Could we not say that movie X has deeper character development than movie Y? Could we not say that movie G is more suspenseful than movie H? This would at a minimum show the feasibility of making cross-film comparisons even when people disagree about their likes and dislikes.
You are taking the idea of subjectivity further than it needs to go by attempting to apply it to all comparisons, evaluations, observations and criticisms. You showed this tendency in the other thread where you mentioned "...a completely subjective arena such as filmmaking..."
If you like Jail Bait better than The Asphalt Jungle or Vertigo or Saboteur or Shadow of a Doubt, you are certainly entitled to those opinions. But they are not going to end any discussions by philosophers of film or critics of film or even amateurs like us here. Such discussions represent no confusion of opinion and fact. Today I looked up aesthetics on the Stanford Encyclopedia of Philosophy web site. It's an area that has had contributions from great minds for thousands of years. The philosophy of film is quite new, relatively. That's quite open to new ideas and contributions.