One of the problems we face is that the definition of abuse generally varies by the age of both the abuser and the abused. Thus people classed as abuse may only fall into this category because of the age of the child, and the fact that the older person committing the acts should have known better. Similar conducts between consenting adults bears no criminal liability.
Additionally, many recent headlines about teachers "abusing" their students have been about a woman carrying on a sexual relationship with one of her pupils, contrary to the notion that women aren't abusers.
Lastly, our newspapers have been filled with cases where otherwise well meaning social workers and foster parents lose complete track of each other. This is frequently due to case overload of the social worker, so that behavior that could have been caught early, had the two enjoyed a working relationship, ends up with children abused or killed, and everyone asking what went wrong.