I'm trying to imagine anyone actually running around in the "picnic pants", with the looks on most people's faces, trying to figure out what they were seeing.

As to pants that look like they were designed with some functional idea, there was a design I saw just once in my life. I was working in a shoe store when a woman customer came in wearing jeans. The zipper ran plainly visible from the beltline in front to the beltline in back. Must admit, I couldn't stop imagining the possibilities.