They have made gestures to keep us appeased, if not appraised.

[In other words, they were not exactly slavers; catch more flies with honey. Bribes were often involved for their cooperation, as it was.]

Considering the state they are currently in, they may well have lost sight of critical facts over time, perhaps to escape the horrors of their own existence. To them, we may yet still seem delicate, despite whatever unique circumstances we may have been obtained from.