Again, I didnt mean to denigrate the profession and I see I came across harsher than I intended, I'm just saying that people are too quick to victimize themselves and hand over all responsibility for their health to someone else. Its the same failure of critical thinking that gets people trying to "open happiness" and start the practice of 2 litres of soda per day.
While I dont think your example of engineers and bridge building applies (the human body is not an assemblage of parts, and your body is yours and yours alone), you should definitely follow the recommendations of accredited professionals, but your ultimate barometer should be your subjective quality of life, which nobody experiences but you. That is what you should attune yourself to, ideally from the beginning so you dont end up in trouble in the first place. I think we'd agree: Prevention > cure. Prevention depends on an individual believing they can affect their health through their choices, not unconsciously moving through life because modern healthcare will "fix" them if something goes wrong.
I'm of the school of thought that believes diabetes doesn't need to exist if you make the correct food choices, and while the lesser of two evils is a step in the right direction the end of the road is still a long way away.
My SO is an RN and diabetes educator and believe me she gets frustrated to no end with clients who are so uneducated about nutrition and so unwilling to change and so locked in a sense of powerlessness that it makes us both depressed.
I am on my way to becoming a nutritional professional myself and IMO there is a place in the industry to tell people what they need to hear, but also to push them to realize that it''s their food choices that put them in this position, and it will be their food choices that pulls them out of their dilemma.
Dieticians are awesome, but your health is your responsibility alone.