You have written a very thought provoking post, Amy.
Women getting treated with "silk gloves" and mainly/only learning the softer part of the art is very, very common. And it is a problem for women who really want to learn the full art.
Recently, I started training with new beginners. There are several girls and one guy. I was very gentle with the girls, but almost in full strength to the guy. My sensei warmed me to be mindful that he was just a white belt when he saw that. I'm not trying to make excuse for myself, but I feel like my full strength was just right for him, because of our size difference. My question is that, am I wasting my time and the time of those girls by dancing with them? Am I helping the guy when I treat him like my level? I'm just a low level blue belt. I felt that if your partner give you their full strength, you learn more from them than if they lower their levels to yours.
You are probably doing what your sempai have done. But it would have been better for your learning if your dojo mates hadn't been so overprotecting, right?
So if you want to help those girls, you should treat them the same as the guys. Beginners of both sexes should be treated as beginners. Just how that is done depends of the pedagogic set used by your teacher and your dojo.
You are really insightful to see this. Most people don't. You have the potential to change your dojo to become a better place for women to practise in, than what it currently is. Congratulations, and good luck!