I think one source of anti-science behaviour might be betrayed expectations. I know that I personally have stronger expectations for academia and scientists than for other people. So when someone from academia, a scientist, an engineer betrays these expectations, I feel worse than if a regular person did it. There's a feeling of "If we can't even count on those people, what are we even supposed to do?". For example, at the beginning of the COVID pandemic (around January 2020), I read a lot about it. Lots of very smart people were saying that this could be a big pandemic. I talked about it with a doctor in a non-professional setting that told me to basically not worry about it, that it wasn't going to be anything huge. This time I was right and he was wrong. Was it because I searched more about it? Was it just luck? I don't know. But I know that it made me lose a bit of trust with that person.
I think the origin of this might be on how I (or we) see those people. You're supposed to follow what the doctor tells you, what the scientists tell you. But in a way, since you're supposed to follow what they say, they have some kind of responsibility towards you. And when they say something wrong, it's way worse than when a regular person says something wrong. It's like when you're young and your teacher or your parents are wrong, it's very frustrating.
Your example about the sugar industry is also a great one. Try to understand a bit more about nutrition, and soon you'll hear all kind of conflicting advice and explanations from very different experts.
I know that personally I have to work on myself and accept that those people are humans, and make mistakes, just like me. But just like telling people to eat less and move more didn't solve the obesity epidemic, I'm not sure that this solution will scale to a large population.
This is interesting, and I've seen a bit of this sort of behavior, too.
Some people seem to confuse expertise for a claim of infallibility, and when some expert get something wrong, the reaction is to conclude that expert advice is worth no more than the guy on the teevee hawking vitamins and anti-expert bile.
It is a sort of Leveler belief wrapped in a search of an Oracle.
Something you may be more familiar with is people's concept that someone that "knows computers" is familiar with any and every sort of task that involves a computer whereas in fact this could encompass a wide variety of different skills that require an individual investment of time.
The same can be said of medicine where encompasses a very broad set of skills. Your doctor may have been an expert in sports medicine or brain surgery but it doesn't automatically make him competent and epidemiology. It also doesn't force him to pay attention to current developments in the news which is likely what informed your opinion. Personally I found it was completely obvious in January that we would be dealing with a crisis because I followed the situation and suspect strongly that your doctor friend did not.
There is also the issue of survivor-ship bias. We worry about many things and we will absolutely recall the times our worry was justified and forget when it we are mistaken. If Yellowstone ever blows there will be many people who knew it was just around the corner and this will be true if it blows now or in a century, whether or not we have any scientific basis for the thought process.
TLDR: A singular doctor of unknown specialty getting it wrong in January isn't a flaw in science. Science isn't expected to be very good at ensuring a single expert of only tangential expertise gives you the right answer whereas it is reasonable good groups sometimes slowly arriving at increasingly correct answers. If you want a more correct answer consider consulting or reading what several people of relevant expertise who are up to the minute on current information have to say.
I think the origin of this might be on how I (or we) see those people. You're supposed to follow what the doctor tells you, what the scientists tell you. But in a way, since you're supposed to follow what they say, they have some kind of responsibility towards you. And when they say something wrong, it's way worse than when a regular person says something wrong. It's like when you're young and your teacher or your parents are wrong, it's very frustrating.
Your example about the sugar industry is also a great one. Try to understand a bit more about nutrition, and soon you'll hear all kind of conflicting advice and explanations from very different experts.
I know that personally I have to work on myself and accept that those people are humans, and make mistakes, just like me. But just like telling people to eat less and move more didn't solve the obesity epidemic, I'm not sure that this solution will scale to a large population.