I think that trying to codify the discussion in terms of whether things were made blatant or overtly fought for or whatever is missing the point. Ingrained discrimination isn't blatant. It's something that people take so much for granted that the question doesn't even occur to them. Often it's the unexamined prejudices that hold people back, even more than the acknowledged ones. For instance, TOS challenged one set of gender preconceptions by having women included on the crew of a military vessel in the future, but left a different set of gender preconceptions unchallenged by having those women mostly limited to conventional roles like nurse, operator, secretary, and the like (plus the occasional pretty scientist who was really just there to be a love interest). They just couldn't see far enough ahead of their own cultural status quo to recognize that those assumptions would come to be challenged later on as well as the others.