Is it necessary to null an instance on quit?

static var instance : LevelData;

function Awake ()
	// Find itself
	instance = FindObjectOfType(LevelData);
	if (instance == null)
		Debug.Log ("Could not locate a singleton object in the scene.");
	// Retain between scenes

// Ensure that the instance is destroyed when the game is stopped in the editor.
function OnApplicationQuit() {
	instance = null;

I’m trying to understand a JS singleton… I’ve condensed the basics down — from the unity wiki — into the above code and it works well but I have a niggling question. It has that function: OnApplicationQuit, null the instance — Isn’t that redundant? Wouldn’t it be emptied upon game quit anyway or am I missing something?

I certainly can’t see any reason for it.

when the editor closes game simulation the garbage collector takes care of everything anyway …
so there is absolutely no reason for this … i’ve never done this and i’ve never had any problems