Holy fuckballs.
Everything asked has been answered, and could have been avoided if the OP had done a little looking around the forums.
Nintendo has this silly idea of tying the digital content to the system, rather than an ID. Maybe that'll change, but for now, them's the breaks kid.
It's called DRM, it's everywhere anymore. Nintendo knows some people would just copy games rather than buy them (shocking, I know), and even though they're a big corporation with more money than you or I will likely ever see in our lives, it's made of of people who may or may not love their jobs, but definitely need to support themselves.