I think because it’s assuming an outcome before the results? I’d say everyone is for people of both genders being treated equally.
But this is not true, historically, and still today. Most people in (in some cultures) may be for treating genders equally in a lot of aspects, but I don't have to go very far on the web or IRL to find people who are not for equal treatment of genders.
But for everyone who does want to treat genders equally, learning about unconcious bias should be helpful. Learning about unconcious biases enables you to question your behaviour in order to actually treat genders equal instead of just agreeing that they should be.
Some of these are biased against women while others are biased in favor of them.