This is the way I see it: It's the point of reference... When you are 7 years old and have not amassed a ton of understanding of what is considered sexual abuse, I believe the brain does not equate those acts as sexual abuse.
Your statement rings true... At that age, I believe, we all know what's considered to be right or wrong, and I believe Wade knew that what they were doing was wrong as it was always done in secret and not in the open.
As adults, with all the years of experience of what we have heard, read, and seen, we have a good understanding of the sexual abuse concept. As a 7 year old child, without that understanding, it's hard to see it as abuse, when you can bring other feelings to the front of the brain and mask it with it was lovely, it was sweet, it was fulfilling...
I believe the audience was mostly filled with survivors of sexual abuse... Another subject that has been on the news lately is the number of priests that abused children for years and rarely you had that on the news because there were too many factors suppressing the truth...
Well, those are my two cents...