>> Why is it “arrogant” of them to come up with an estimate for the size of the galaxy?
And then call it what it is — a best guess based on incomplete knowledge?
Nothing at all wrong with *that*.
But that’s not how the writers frame it.
I do agree that they often prematurely come to conclusions and state that various things are fact when the reality is far from it. The history of science is littered with such premature conclusions.