For thousands of years birth sex became a tool to suppress and to uphold. It was the most essential divider of humanity into strict and immovable roles. Now for the first time in our history this has begun to change, and our merits are not as weighed by those metrics as they once were. When society became less about plowing fields and bearing children, we could begin to look at individuals based on characteristics others than those tied to their birth sex. Of course, this evolution very much perturbs those who still hinge their philosophies on what males and females are supposed to be like and do. The increasing visibility of trans people is yet another reminder to them that the world as they knew it is changing which represents a threat they cannot accept.
My generation and certainly all before were very much defined with strict gender roles and we bought in as just part of the inherent way life was. The idea that there were supple edges and grey areas never occurred to us and when you disobeyed you were quickly and dutifully reminded of the sin. Both men and women understood where the boundary lay, and we accepted it as if it were determined by our very DNA. We simply did not know better or imagined there were other possibilities.
Today we understand the distinction between gender and sex very well, and it seems entirely logical to decouple them but, as with every major social change, it takes many years before a realization in thought becomes a concrete and observable reality that we eventually simply take for granted.