Same institutions endorsed smoking tobacco, condemned eating healthy fats, advocated for pancakes, bacon, orange juice as healhy, and many more false and incorrect conclusions that ended up hurting millions of people. They all walk in lockstep, and doctors have a little of a cult thing going on, which means it's not hard for them to prioritize their institution and profession over the truth. Then there is the incentive of profit, and we all know people will go to lengths for money, so it's not crazy to think the industry as a whole is making a huge mistake.