There are plenty of "actual facts", spoken by "experts", which a few years later turn out to be absolutely false.
They thus are left to resort to authority as the proximate measure accessible to them to assess how much credit to assign to the opinions of a particular expert.
To complicate matters, there are documented cases where in the past half century at least experts have be bought by special interest groups such as big tobacco etc. This eroded public trust in any experts and many people were brought up assuming every public discourse with expert opinions is rigged. That generation now 40-50yo and their world view is having a certain weight on current matters. (Disclaimer: this is just my personal opinion, I'm not an expert. And even if I was many people wouldn't trust me anyway ;-p )
It’s also easier to set up an apolitical body that makes recommendations based on research than it is to have everyone draw their own conclusions or devolve into “blue science” vs “red science”
These are mechanisms that cultivate public trust, and there are countries that do a pretty good job at it.
From my point of view I think that is a healthy reaction against technocracy, and it's not US-specific. Those "doctors, scientists, and professionals within certain fields" can't expect to take the decisions that influence the life of millions each and every day, with almost no over-sight, and then complain when people question those decisions.
"But science says that we should do that and that!" is not a valid enough reason anymore, because science has "said" lots of things that have been proved to be very bad to some parts of the populace (see eugenics, which has been demoted to "non-science" after the fact so that those technocrats that had tried to implement it could wash their hands off of it).