Let me add my two cents:
A movie (or any piece of art) can be objectively bad or good. There are plenty of aspects in which, say, Attack of the Clones fails. This is the objectivity of art. Bad dialogue, acting, and storyline make a movie bad. These things are basically what makes a movie a movie, and failing at that is enough to call a movie “bad”.
However, you can still like an objectively “bad” movie. For example, Sharknado is an objectively bad movie, but I still kind of love it sense it entertains me. A movie’s “bad” or “good” status doesn’t hinder your ability to like it.