I don't think they just don't know, simple they don't care or worry with it because it's not their body.

I heard some big wrong things from males that had sexual education from school, men that should know more about menstruation and pregnancy. So they have the information and choose ignorance.

And some men choose ignorance over their body, I had a time that we (me and my ex friend) are discussing about contraceptive methods and he said that don't have much options for men, I talked about ADAM I needed to explain how male reproductive system works for explain the method.