They didn't exist before the calamity, the conflict between Hydaelyn and Zodiark was the very first conflict in their history and it is said by one of the shades.

However you could say that he's an hipocrit because he prefers to mingle with mortals than with his peers and his actions shows him taking a more active role in our society even to the point of siring children.
For someone that loathes us that much his actions are odd