Because those who need to imagine this lie think that if the conquerors were not 'noble', etc., then neither are they. They imagine themselves as direct descendants and resist growing up about the unpleasant facts. I guess that's the kind of 'minds' (if one can call them that) produced by 'Disney' education. It must be addictive as those most deformed by it crave to have it exclusively as 'education'. Now THAT, indeed, is not education but indoctrination!!!