Hello, I don't speak for all women, obviously, but as a woman who plays this game a lot, I often find we do not talk because when we do, people will begin to sexualize our voice/anything we do and be incredibly inappropriate, among many other things. Be straight up sexist in terms of in-game ability or a woman's role in society, molly or literally corner us so we can't play the game...
Other things are more implicit: do not listen to what I will say but if a male counterpart says the exact same thing, that's a great idea we should do that! Constant backseating of me but not my fellow male players (and it's like "plant the bomb" type things ... EXTREME micromanaging that the other people do not get.) And if I ask them to stop, they don't. Ignoring them doesn't stop. If you mute, they molly or just throw.
That being said, those are just bad experiences that have happened enough for me to watch what I say. Of course, I have had fantastic teammates who are men who make me feel safe and stick up for me when that happens. (LoMein, if you see this, you're a real one I haven't forgotten you!)
Just trying to offer my insight. We just want to play the game and the best way to do that sometimes is not using our mic. It comes down to our enjoyment and, honestly, safety, sometimes.