One hundred years ago, everyone believed that there was only one galaxy in the universe. We now know this to be false. (Very false.) I am not aware of anyone who believes that astrophysicists from 100 years ago were idiots. They drew the logical conclusion from the information available to them, and when new information became available, they recognized that the conclusion they had drawn was incorrect and discarded it.
I, for one, certainly don't see them as idiots. They're the giants in the phrase "standing on the shoulders of giants." Without their work, in an age of far less precise equipment, we wouldn't be where we are today.
And just as it's turtles all the way down, it's giants all the way up.