"Doctors are idiots following algorithms and don't actually have any knowledge or information and just scam everyone for money all the time until their eventual replacement by the first person who thinks of feeding electronic medical records to machine learning algos" would cover about 95% of HN comments in these sorts of threads. You might cover another 2% with variants of "there's no point in going to a doctor for your problem, any decent engineer can just spend a few dozen hours reading up on their problem and figure it out just as well."

It's gotten to the point where I only chime in once in a while when the thread has gone deeply, deeply, off the deep end. But then, HN seems to have variants of that attitude towards pretty much every profession that doesn't have an engineering degree.