That's a good point, but do you think that after a visit or two, any reasonably intelligent person is going to get an idea as to whether one is carelessly ignorant about the basics or not? I'm not talking about whether the pediatrician can get a full CV from a patient, but whether s-he could make a decent guess as to whether or not one knows, for example, that toddlers need to consume more than rice milk? I think so. I really disagree that the solution to a few idiots is to treat *everyone* like an idiot, or be to blame. This isn't a binary situation.
I suppose I don't consider being able to diagnose oneself with PND to be anything close to the level of ignorance of the OPs example. PND is not something that a layperson can reasonably be expected to know much about and even if s-he did, it's famously difficult to self-diagnose.
I guess we're debating where to draw the line. I personally, would expect that it is reasonable to buttume a baseline of general, easily accessable knowledge, and I disagree with the notion that one must buttume that everyone is an uninformed idiot, or be to blame somehow. This kind of argument obviously strikes a nerve with me. :)
Donna