Do you shoot with the other eye open or not?

If you were supposed to shoot with the other eye closed, then why isn't camera design inverted, like the viewfinder is on the other side of the body so that the camera naturally cover the other eye?

I think it's uncomfortable to have one eye closed over larger periods, so when i do manual focusing, i would love to keep my camera upside down, but then the shutter button is on the bottom and i look like a retard