>>22434813emulation happens as a result of the hobbies of people who either really really love computer technology, or really love video games and just happen to know a fair bit about computers. Some emulators have been getting developed for years and still have bugs.
It takes way more power to emulate a game than the original system needed to run it natively. A 3ds emulator would basically have to model a digital version of all the computer parts. On a real 3ds, none of that modelling happens because the actual physical computer chips are sitting right there. Taking shortcuts and emulating the hardware less accurately makes it easier to get any particular game running but makes the emulator more specialized towards running a particular game. It's possible to have code for emulating one game that doesn't run another game at all if you do things a certain way.
I think a serious attempt at a 3ds emulator just got its first game working properly, but I hate my phone and my laptop so I've got relatively little emulator experience. Maybe we'll see functional emulation for the 3ds around the time the next handheld comes out, or a little later.
