I think the statement "it doesn't dissuade you from doing potentially dangerous things" is the key point...
I have engineers curse, I focus on outliers. This is the fundamental problem I see with the push we have in medicine/health today. It is a focus based on the premise we are all basically the same biological machine. As you start to shrink you viewpoint down to the molecular part of that machine, the differences start to become rather significant.
If I declare something absolutely "bad" for you, well, no surprise if you do it and something bad happens. That is exactly what I would expect. When it comes to diets and sensitivities to cholesterol, smoking, sugars , alcohol, fats, carbs, etc., there are a "lot" of outliers. So many that it makes me question the validity of the foundational argument, we are all the same and fall under the same standard distribution. I suspect that there are, much like cancer markers, much stronger sensitivities in our molecular machine works that will really drive what hurts and what helps us. Consider cholesterol, every doctor today will want to slap you on the current fad cholesterol drugs, and yet, we know that there are absolutely cholesterol sensitivity markers that are passed on. I recall a study that had some interesting results based on your markers (say american Indian/Asian vs European) things like drinking alcohol, good for one group, harmful for the other. Exercise was another one, aerobic vs anaerobic was very different ratio based on markers to get benefits. carbs were the same from one end of the spectrum to the other; one group needs low-fat high cards, the other, high fat and low cards!
I agree that we only know what we know, but the issue may be not what we know, but "who" knows it to help each person. If your doctor is only treating you as the midpoint of the distribution, they can be really off the mark. Sadly, no group seemed to be high fat and high carbs Oh the agony, I hear the doughnuts crying out...