Gender imbalance on it's own doesn't say everything. You should actually talk with women in STEM. Many of them shared their horrible experiences so far.
My point is that we shouldn't be surprised by a gender imbalance on priors. By itself, a gender imbalance only goes to show that software engineering is like a lot of other jobs.
BTW, my suspicion is that similar experiences happen in many industries, and industries vary according to (a) how horrible a given experience is said to be and (b) social norms around registering a complaint.