Honestly, it seems unfair. And as someone who has both handed in my 2WN, and been fired, I don't see why employees aren't given 2 weeks notice before they're fired. I understand why I was fired at my first job, I was a young teen who liked to mess around a little too much. But now that I'm an adult, these two ways of leaving a job are not equal. One requires you to type up a message, work for two more weeks, and then you're done. The other just skips to the last part.
TLDR: 2WNs are terrible when you can be fired whenever.