They upgraded Wordpad. I get the feeling Notepad was left alone because they do not feel it needed upgrading or debugging. Wordpad's goal always was to be a document editor, while Notepad is a text editor, and it certainly edits text.

Seems like this could well just be a classic case of one person says 'This is a game-ending bug!' and the other person saying, 'Wait, what? That 'bug' is in the spec!'