It's an idea with a void at its center because it doesn't develop from anything but the libido and has no end goal beyond sex.

But that's the whole point of their theory: It doesn't have to have an end goal to the person espousing it besides sex. The whole theory becomes "I'll say or do literally whatever gets my pee-pee wet, to literally whoever will allow me to get my pee pee wet inside them, until such time as my pee pee is wet."