Great question — answering as the UphillTech team:
Some of the older Bond girls were comic, for example Goodnight in "The man with the golden gun" and Rosie in "Live and let die". Today many of the jokes appear sexistic, although they are probably not worse then Bond's attitude towards women (which has changed a lot since Roger Moore). So I guess that cultural change plays a role. Another reason could be that the stupid woman is still used as a stereotype, especially in sitcom. Any producer considering himself "serious" would want to avoid being considered "trivial" comedy, thus avoiding stupid female characters. Also the two peasants from "The hidden fortress" could have influenced the way we see comic relief, either directly or via R2D2...
Full answer by Jan-Christoph Schlage-Puchta: https://movies.stackexchange.com/a/63469 (CC BY-SA 3.0).
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