I think we insist on saying that art is either good or bad because it has to mean something and if it does than each one cannot portray that meaning equally. People often think of art as a way to express emotions and some expressions of emotions are stronger than others. Some people think of art as a way of communicating emotions and some must do this better than others. If art is just lines and shapes and colors than one example is not better than another but then art is pointless. I think art has to have emotional content and if it does not than it is bad art. If every work of art was created equal then no artist could be really respected in their field because they could never be better than average. Everyone would be the average. There would be nothing to strive for. In order to know whether a work of art is good or bad if first needs to be determined what the goal of that piece of art is. The degree to which it reaches that goal would determine how good or bad it is. If a piece of art is made to portray a social message and manages to do so it is likely a good piece of art even if it is not aesthetically appealing while a work that is meant to be aesthetically pleasing is a good work of art if it is for many of the people that view it. I do not know if all art should be held to the same standard or if art has more than one purpose. Maybe it cannot be defined because as such a broad category the different categories are not only different in their methods but in their intended purposes. Art is a difficult concept to define and until it is defined it cannot be known what is good and what is bad, but if nothing is good or bad then art can never be judged. If it can never be judged no work can be superior to another. In a practical sense this would be bad because art chosen to be in a museum would be completely arbitrary. There would be no reason to choose one piece and not another, so museums could have no standards and would be unjustifiably denying anyone they did not include in their exhibit.
Does this make sense and what other reasons are there for determining whether art is good or bad?