Once all the exalted people of the world pronounced it flat. They were wrong as well. Facts are not subject to consensus, even the consensus of those who hold power.
The only people who know the truth are the ones who have researched it from it's origins, not those who simply seized upon the Opinions of others hundreds of years later.
Your argument involves a curious combination of “the entire world determines citizenship the correct way” and “the entire world is full of idiots.”