I don't buy into the initial premise. I'll be brief:
1. There is more than just tactics. There is mindset. Women may come to the class with a different starting point than men. Establishing mindset from two different points of view may take different specifics.
2. Men tend to posture in class. One might say that a good instructor can control that but I don't think you can control subtle pressures and behaviors. Not worth fighting about for beginners. Some feminist gun books are full of male idiots spoiling range time for women.
3. Women, as mentioned above, come to game with issues of victimization. They may not want to share with men.
That's the reason for separate beginner classes.
As far as racism being more dangerous on a subtle level - not to divert - but horsepoop. Tell that to the dead, tortured or those who were denied jobs,etc. Yes, there is implicit and explicit racism. Explicit makes you dead or live in a ghetto.