Women are show as art, beautiful lines, curves, eyes, mouth, they're on magazine covers, they're on top of cars for marketing purposes, they can do anything and enter everywhere, complete goddess.
Men, are seen as hard, blunt, difficult, sweety, sometimes unpleasant and harsh. The way society views one another is completely different . The woman can be so magnetizing that even they are drawn to each other, and it's understandable.
The way society shows the two genres is what leads to more woman being bi, especially because it's accepted by all.