This T-shirt company was started by poet Derrick C. Brown. All concepts are by him and most were thought up during long road drives while on tour. It is very possible someone else thought of the same idea, but that person would have to be not so bright.
You can find his work written poetics at brownpoetry.com
Also, the women's and men's section just refers to the cut of the shirt as referenced by the shirt company and any shirt is welcome to be worn by anyone of any identity.