I was in a little takeaway restaurant earlier today near where I currently work in a somewhat dodgy area.
A young man, maybe 20-25yo ish, came in ranting to himself a bit and possessing the space around himself aggressively with arm movements, side steps etc.
Every woman in the shop moved away. The woman sweeping the floor near him looked up sharply when the aggression became clear and moved quietly but quickly away. The men mostly didn't move.
I had no concerns about the contents of his trousers. I gave not a thought to his genitalia. I thought a lot about him being bigger and stronger than every woman in that cafe. I thought a lot about how dangerous an angry man can be in an enclosed space. I thought a lot about how carefully the floor sweeping waitress moved away to avoid drawing the man's attention to her moving away from him. I checked my exits.
In that same shop I have seen women come in similarly. Salubrious place obviously The reaction from the other women, from myself, was no where near as extreme. The risk of devastating violence from a woman is much lower. I'd face up to most if it came down to it.
It's about the height, the arm reach, the biceps, the propensity to violence, the tendency towards violence when female rejection/disrespect is perceived, the low chance of me standing a chance if he decides to have a go at me. Genitalia are irrelevant. It's the whole of his male body and his male aggression that worries me in a way that women don't.