No, his point was people shouldn't talk with _absolute confidence_ about things they don't know about.
Usually in everyday life we hint at our confidence level with the language we use: 'might', 'probably', etc. These people have trained themselves not to do that, which they previously have gotten away with.
As an immigrant, and I'm sure many foreigners would agree, this is extremely American.
People, gentile people, who use "might" and "probably" are weak intellectuals by American standards. They are cast aside, especially in media, because they cannot give definite answers. This is science and science doesn't sell.
Politicians and media types are sales-people.
This really depends on the family and milieu you grew up around and are engaged with generally in life.
This is actually career advice I was given as a kid by an engineer at a nuclear power plant: “don’t give the impression that you’re uncertain during discussions even if you are.” I remember thinking “isn’t it literally your job to be uncertain?” That really bothered me and I’m reasonably sure I wasn’t wrong to be bothered.
Usually in everyday life we hint at our confidence level with the language we use: 'might', 'probably', etc. These people have trained themselves not to do that, which they previously have gotten away with.