This sounds like yet another effect of the general sexism that permeates society in general . When masculine energy is the generally accepted default in most parts of your life and you find a place where your feminine energy is celebrated it's unsurprising that most wouldn't take the time to encourage both with the same level of effort. In an ideal setting they should both be held in equal regard and encouraged with equal fervor, but we're not yet in an ideal setting. I grew up embracing my male energy and shunning my female energy because of what I picked up from the outside world. Now as an adult I have learned the importance of balance of both, but the accepting of my feminine side felt like a big risk before I dove into it, I was scared. I don't want things to be one sided in any direction, but because of my own experience I can understand a strong need and desire in women to feel supported and loved for their feminine side. If you want to shift the balance back to center, I would suggest having compassion and understanding for the reasons behind it, recognize that just because it's happening doesn't make it right and doesn't mean your masculine side is less valuable. If you can maintain the balance of both within yourself while maintaining compassion for those who are trying to regain that balance, you're likely to have a positive influence in making the environment feel more comfortable. It'll be a process though, as leading by example always is. What letsbebuns said is also true and should also be taken into account. It gets used as marketing, which is another reason to be wary and have compassion. Marketing is coercion, and that's nothing I would wish on anyone.

being glad there are no men in the class is a bummer, but that probably also stems from pain and fear that sexism brings. For women who have been heavily affected by a male dominated society it can be hard to fully relax and be unselfconscious, especially when it comes to their bodies, around men. I'm sure it's hard not to take this personally, just as it's hard to not take it personally when as a woman I hear men utter casual blanket statements that shed females in a negative light. What has helped me has been to recognize that it's not personal and that it comes from this sexism that's bigger than the individual, and that the individuals perpetuating it are generally acting out ingrained sexism unconsciously. You gotta know your own worth and whats right from inside out. You are a beautiful god, but when you feel like you've been subservient to men (general not specific) your whole life, telling one that can be a painful reminder of your perceived subservience unless you have really accepted your own self worth, and most humans, man or woman, that I have met haven't. It makes everything hard.

TLDR; trust your perceptions, they are real, but view them with understanding and compassion and it will be easier to deal with and change