All Rise! Higher, Please!

I just accidentally bought two pairs of medium-rise mens' pants. I didn't even realize there was such thing as medium-rise pants. At least until I put them on. Then I realized pretty quickly that they were a little tight around the, um, "inseam region."

What is the idea behind low-rise mens's pants (there were some of those at the store too)? Please help. I'm not being rhetorical. I'm really stumped.