[timwiseman]

In an ideal world, this is precisely what we would do.

Unfortunately, this is a world constrained by time and by knowledge. I do not have the time or expertise to evaluate everything I read in a clinical fashion.

Given those constraints, who the author is becomes a very powerful signal. If Neil De Grasse Tyson says something about astrophysics I can probably take it at face value, at least until I have a reason to question. On the other hand, someone with a self-interested reason to get me to believe something will rightly get far more scrutiny, even if they are eventually proven completely right.