And/or they simply want to avoid a direct confrontation, which might happen when a man is present, but not when the woman is alone. This just happened to me today, biking and of course i heard some rude comments. Really wanted to tell them to fuck off but then I would engage, they might respond, etc, and my biking zen would be even more disturbed.
It's really not "that guy might stop me". It's "they're probably a couple, what's the point". The default assumption is that a mixed-gender pair of people around the same age is a couple. I've been out wandering with female platonic friends plenty of times, only to have people assume we're a romantic pair.
So you think a woman walking with her father would get catcalled like a woman alone?
Do you think a woman walking with her mother would get catcalled like a woman alone?
Contrary to the success always obtained by catcalling?
I just skip catcalling, because I don't understand it.