That is the problem, the audience should feel terrible about a kid being tortured without the need to watch it. There are many things that can cause a strong emotional response, like good writing and caring about the characters.I get that it was hard to watch. But maybe it was to hammer the point home (no pun intended). By actually seeing the torture, the audience will have a stronger emotional response.
Not to mention the "abuse" as a plot device. "Lets torture a child, that would convince Union to finally kick the Moclans out".
The whole story was about Topa being abused by friends and enemies. Worst of all was Heveena, trying to exploit a kid for the greater good. They should had also kicked her out of the Union..
So in a movie about pedophiles it would be important to see in details how they rape a child?Because it was important to the story.