If you are trying to suggest that children have a sexuality, I agree. I would add to your "attacking" point that any sexual behavior can be a red flag but any sexual behavior that is spontaneous, takes place within a emotional and psychological peer group, is not predatory and is not coerced is age appropriate.
We are not discussing that behavior. We are discussing exposing porn, which is not part of or designed for children's sexuality to children who in our society, are not equipped, and possibly not physiologically able to be equipped, with the tools to process porn.