If I understand the question correctly, I wonder the same thing. Here is what it seems to come down to:
* They are used to hearing this type of language and thus use it without any thought. It’s common language to them.
* They aren’t aware of the implication.
* They know it will create a verbal shock factor.
When a person tells me that I had balls to do or say something, I understand that this is meant as a compliment. As a female, it isn’t taken as an insult. Still, it would mean more if the person had just said something that wasn’t gender-related.
Whether any sexual term is used as a compliment or an insult, my first train of thought goes to what their upbringing might have been like. It could also boil down to peer pressure. All I can tell you is that a person who uses ‘sexually themed’ words goes down a notch in my respect meter. Sometimes I call them out on it; other times, I don’t. It depends upon how much I know and care about them.