Heinlein pretty much mirrored a very common male attitude from around the late 1950's through around 1980. Incidentally, a lot of what we think of as "Fifties" culture is actually more like "Early Sixties" culture. Aka "Camelot," in its highest political manifestation. Notable for its assumption that women existed primarily to please men and men owed them no loyalty for this.

The actual "Fifties" assumption was that the men owed the women a lot of loyalty if said women took care of them. That's the assumption which Boomers found "old-fashioned."