[CTRL-A] is supposed to select all the text in the lyrics editor. Why does this not work?
Not according to the Keyboard guide in the help menu under Lyrics command. It just refers to Ctrl+X Ctrl+C and Ctrl+V.
Keep in mind Ctrl A has another purpose in NWC, it is the shortcut for adding another staff.
It should, because the Lyrics Editor is completely separate from the main window. You can't even switch to the main window when you're in the Lyrics Editor.
Try and find an old copy of 'How to win friends and influence people', and don't say 'It should'. Who are you to decide?
I must admit that I have tried Ctrl-A inside the lyrics editor often enough.
You see: you have a point. Now get it across in a neighbourly manner... please?
I generally avoid answering "why" questions, but here is the explanation for this particular behavior.
The lyric edit boxes are actually implemented as standard Windows controls. NWC does not implement the keyboard or mouse behavior in these controls. The keyboard and mouse behavior is entirely under the control of Windows, although we certainly could add things if necessary.