The trouble is that child abusers/neglecters are a bit like people who have addiction problems. There is a lot of covering up, slyness and lying. There are bound to be some mistakes as there are in all professions - look at the mistakes in the medical profession for example, but look at how many people's lives are also saved and the quality improved.

In a lot of jobs the mistakes that happen maybe don't have such serious consequences.

In some professions the responsibilities are not always matched by the pay - but that is another issue.