A nice feature! I'd vote for it :)
This feature allows to place the cursor behind the end of the line.
Let's explain. Imagine a text contains lines with different lengths. When the cursor is placed on a long line is a position that is greater than the length of the previous line and user pressed "up", the cursor should just move up and preserve the horizontal position (if this feature exists). If no virtual space (as in Microsoft editors), cursor jumps lefter - to the end of the line where it stepped to.
As of which editors implement this - Far embedded editor, IntelliJ Idea, etc.
Customer support service by UserEcho