> But how do they have time to waste voluntarily ruining peoples' lives?
Perception bias. The only time you'll hear about CPS is in a case like this, when the agent is on a power trip and oversteps his bounds. You never hear about the success stories, where they intervene to save a child, or are successful in getting a family therapy.
I can speak from experience here, I have dealt with CPS. When I was notified they would be visiting our house, I did some research. I read the horror stories, and I learned a key detail: CPS is not a policing agency. The threats of taking your children from you and throwing you in jail are idle: only police and judges can do that. When you deal with CPS, only let them in your house if they agree to be recorded. If they refuse, or their supervisor objects, don't let them in. Unless they have a warrant, you are under NO obligation to deal with them. (Bear in mind, though, the courts will probably side with CPS)
But I digress. My experience with the social worker was that she was just as nervous in dealing with me as I was with her, but she was genuinely interested in understanding and offering assistance. She asked a few questions, held a follow up visit, and that was the end of it.