Also "brainwashing" generally implies an efficacy that we didn't see in real world results. The generation raised on shows like Captain Planet don't seem that much more "eco-conscious" than those before or after that period of children's programming. If anything, villains from that show being elected to the highest offices in the US decades later seems to directly refute that it was anything like "brainwashing".

(ETA: Not to mention that the biggest takeaways from such shows was that individual action was sometimes more important than corporate or regulatory action, a message itself designed by the oil companies to avoid responsibility. If there was propaganda in those shows, it may not have been the heroes winning, but the idea that all we need are a few magic heroes rather than government regulations.)