These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
To elaborate - Alan Moore once gleefully detailed the method of murder and organ removal to Neil Gaiman, who had to step outside to get some air so he wouldn't vomit. Twice.
The Woobie: The chapter isn't called The Unfortunate Mr Druitt for nothing.
In the movie:
Adaptation Displacement: Most people had never heard of the comics before the movie was released.
Also, the movie is a fairly straightforward whodunnit film, whereas the in the comic, the Ripper's identity is known throughout (though considering Ian Holm's very recognisable voice, this holds for the film too), and concerns itself with the "why" rather than the "who."
Alternate Character Interpretation: In the end, is Abberline's death from opium overdose just an accident or does he kill himself because he can't ever see Mary again.