Well, it's clearly an echo chamber. There's very little actual transmission of knowledge in those topics. It's almost always about confirming pre existing beliefs. I'm an MD too, but I've been raised by scientists. Scientists in my own family entertain the same beliefs exhibited by HNers, to surprising extremes such as dismissing the effect of even very well understood drugs.

Last year, my father stopped his blood pressure meds and was very surprised when I could guess he'd stopped just by looking at him, then proceeded to explain how the drugs acted, and got even more surprised when he got much better 15 min after taking them again. Since then, he totally forgot about this event and is in complete denial. You can't change beliefs by explanation. People have to get to their own conclusions, otherwise you're just fighting windmills all the time.