Great points! I think that the "phallic phase" of men's lives also supports the view that most men want to see other penises.

The raphe also reminds me of the fact that for millions of years we saw male and female (and intersex) bodies come from female bodies, meaning that she somehow "contains" both. Considering there are only female figurines in most of prehistory, it could be that humans believed we were all version of her.