Umm, no, A New Hope was NOT a kid's film. Maybe you were a kid when you saw it, and it took years for the deeper meanings to dawn on you, but that was not the case for many people who saw the films back in 1977 and after. Many people were NOT kids when they saw it, and they never would have guest it was a kids film.
Yes, Star Wars was mostly family friendly, we have both the use of the words "damn" and "hell" thrown in there, which are not kid's movie words. We have a bloody severed arm, not kid's movie stuff, we also have people getting choked to death. SW was a pretty kid friendly movie, and kids absolutely loved it, but so did adults.
I hope you are not saying the Genndy cartoon resembled the OT, there was really no resembalance. The cartoon was clearly for kids.