May have a theory
We all know wall-e right? We may have seen the cannibalism theory and other dark ones, but I have one that probably hasn't been brought up. What if the repair ward robots are slowly becoming sentient instead of indoctrinated? take VN-GO for example. he tries to paint anything he can. its like hes longing for something different (this is a desire for creativity and color). another robot is PR-T. She has the sort of same desire as VN-GO, trying to give makeovers to anything. from people, to inanamite objects.
We can see this in the movie. VN-GO is splashing paint in his cubicle, he is also seen creating a trail of paint in the repair ward breach. And PR-T gives wall-e a makeover and even other robots. Her desire is nearly the same as VN-GO. Its basically a missing puzzle piece for them. The CARSTIC robots just re-indoctrinize them over and over again.
More examples of them having a desire. V-QM has learned how to sneeze dust freely instead of absorbing it. I dont really have anymore examples, so the end is here.