Yes, there are definitely wackos out there and that's not good for the children involved. There are cases where people have done awful things to kids with their misguided ideas.
I saw my cousin go through chemo treatment with his 17-yr. old daughter, who later died. As you can imagine he has very strong opinions about this subject and what the family is going through in making decisions like this. I'm not arguing with the way this turned out, I'm saying that you are setting two different standards here.
"Would I want the state to intervene if I was one of the idiot parents doing this crap to my kids? Of course not. But being sane, I most certainly do want the state to investigate reasonable suspicions of serious child abuse/neglect, and intervene if investigation finds clear proof that intervention is necessary to protect the child from severe harm."
Sounds like you are saying they have no reason to ever investigate you but it would potentially be warranted for anyone else. IOW, you would welcome the involvement for everyone else but since you are a sane and reasonable person (by your own admission) then it would not be appropriate or necessary for you.
Well since I have no children yet, I'm not a candidate for state intervention re child abuse/neglect. I'm just pointing out the obvious fact that people who are legitimate targets for any kind of state intervention, are almost by definition opposed to it in their own case. But that doesn't change the fact that it's appropriate for the state to intervene. Shoplifters don't like getting arrested, drunk drivers don't like getting their licenses revoked, child abusers don't like state intervention in their parenting practices -- and all of these are prone to denying that they actually did what they're accused of doing.