This is where we may diverge, though I'm not exactly sure what your position is on some of this and I don't want to put words in your mouth.
I think that some aspects of art are subjective, while others are not. If everything is subjective, then there is no definition of the thing in question and we're just in a purely relativistic world. But pure relativism leads to logical contradictions and is not philosophically tenable. OTOH, if something is defined, then there is some base level of rules or standard to which it conforms. Doesn't have to be everything, but it has to be something.
On that view, we can say that while the enjoyment of TV/movies is certainly subjective, there are "rules" to which they should conform, and if they don't, then they've failed to reach a non-subjective bar and may be said to be "worse."
What rules those might be is a subject for the "Philosophy of TV and Movies thread," which I am not going to start.