Mystery Schmistery

Why is it the Mystery genre is flooded with murders? How many times can we sit through a murder mystery anyway? How many creative ways can you solve them? Whatever happened to other crimes that need to be solved? As I recall Sherlock Holmes did far more than solve murders. In fact, I have a hard time bringing murders to mind when I think of the corpus of his cases. Why are we so enamored with killing people and catching the killers?