Causes of a Bad Movie

HOW DO YOU TELL IF A BAD MOVIE IS THE RESULT OF POOR DIRECTING, ACTING, SCREEN WRITING, OR SOME OTHER REASON? That was the question on Quora. I dared an answer. But it was also a learning moment, so I'm editing it bit and posting it here.

To answer such a question we have to first rid it of equivocations.  What do we mean by "bad"? Is that a pejorative or a compliment?  Assuming it's a pejorative, what or who claimed the movie was bad? A critic? Box office gross? Awards season?  A niche audience?  Let's assume it's the box office. That means the movie did not connect with audiences, or it was poorly marketed.  But let's generally say that it was marketed well, but audiences refused to give it word of mouth promotion—yes, it was a bad movie. So, why was is DOA?

Let’s look at 7 reasons, any one of which can minimize a movie’s success or ‘add’ to its failure, but only one of these will kill it directly