Many people never want to recognize that kids in general (boys mostly) have a very tough time with frustration. And the frustration stems from not getting something or an outcome they want without receiving an explanation they can really understand. Most adults give lip service to explaining things to kids. So kids (again, mostly boys) want to lash out violently against what they don't like.
Partly it's just human nature to turn to violence as an outlet.
Now, sexual violence? This is a frustration with the opposite gender, and these frustrations start far earlier than most people would think. In pre-school girls and boys learn about their differences. Often times, parents unwittingly add to the problem with their own gender biases. And that's where a lot of this comes from.
Is using an AI as a violet outlet good? That's a complicated answer. Certainly kids doing this need some help by way of understanding and explanation. But, like the correlation between violent video games and a reduction in violent crimes (or even pedophiles using child-like dolls for their sick outlets and thus a reduction in pedo crimes - and yes data does support that), a digital outlet for violence can be a good thing.
But it needs to be monitored by responsible adults and the kids need understanding and help to work through their frustrations.