Robert Louis Stevenson - Dr Jekyll and Mr Hyde

In Victorian London, where the exposed curve of a table leg was considered indicent, pornography was more popular than ever before. What better metaphor for this utter duality than the story of a doctor, plagued by vices, transforming himself into his 'evil self', a liberated monster who takes over his neutral alter ego?
What’s interesting about Stevenson's novella is the lack of explicit condemnation for Jekyll's experiments; indeed, there's an undisputed claim that evil is inside us all, better acknowledged than suppressed.
But, classic or no classic, I found the narrative lacking and not worthy of the strong underlying idea.