Throughout the 3rd Westworld season, we are shown an AI technology (Rehoboam) capable of predicting everyone's future, hence the direct implication that humans don't have too much of a "free will" left. Rehoboam's only "vulnerability" seems to be the hosts. Yet, Ford was a human and not a robot, and his critique of humanity was obvious from the beginning.
He even tells Bernard during one of the first episodes that he thinks mankind has already reached its limits. Furhermore, he even kills another human being simply because she was in the way of the hosts and at one point during the 1st season, he tells Bernard that humans were so aggressive they "ate" the Neanderthals.
Rehoboam was in a full "protect the humans" mode all this time. Why didn't he do anything to stop Ford from accomplishing his plans or at the very least consider Ford a 'red flag' and eventually inform Serac about his intentions to liberate the hosts who were posing a great threat to humans in general?