Actually, Sciencegeekgirl.com adds VERY MUCH to the article, namely a highly interesting discussion of WHY students give these wrong answers. No, it's not because they're stupid or ignorant.
They may not be stupid, but that's pretty much the definition of ignorance.
The interesting part is the discussion of what these wrong mental models look like and how you can teach a correct one.
By modern standards, absolutely.
By your definition they're ignorant, but not stupid?
Absolutely. There was much they did not know, as is true of anyone. "Ignorant" is not an insult, it simply means you do not know something. Would you say Aristotle and Newton knew everything about everything? If not, then they would be, by definition, ignorant of the things they did not know.