The most frustrating thing to me is the authoritativeness a lot of these people (including people who are legitimately scientists) speak with. They will say a thing with that authoritativeness, then be conclusively proven wrong, then say something else with that same authoritativeness without any sense of self-reflection that maybe where there is uncertainty statements should reflect that uncertainty.

That was a lesson I learned fairly early on in my professional life as an engineer, and it's unfortunate that so many far more seasoned scientists and engineers haven't learned that same lesson.