It's essentially something that 343i has added, but the Librarian's dialogue in Halo 3's Terminals with the Didact carries the implication that the Forerunners have had a pretty negative effect on the races they were supposed to protect. [quote][i]Can't you see? Belief in the Mantle sealed our doom! Weakened our [protectorates], bred dependence and sloth. [b]Our [so-called Guardianship] has stripped those we would keep safe of any capacity for self-defense![/b][/i][/quote] This can be applied perfectly to the situation with Ancient Humanity.