From a cognitive science perspective, why is this behavior idolized and even defended?

A female with her tits out wearing leggings walked past me and my gf told me that the female had a nice top. I said she looked like a whore and then she got upset at me for being so harsh.

Fact 1: the female was probably doing it for attention as it was cold as fuck out
Fact 2: Whores make for poor mothers and usually lack family values, making her useless to me and others who share the goal of having kids
Fact 3: This female was a complete stranger to us, she talks shit about "creepy" men yet me calling this cumbrain a whore was out of line?