I just think it's:
Unaligned is an option. You haven't devoted or stuck yourself in any extreme.
Or you can do any of the classic alignments if you see your character/monster filling those shoes:
Lawful Good
Neutral Good
Chaotic Good
Lawful Neutral
True Neutral
Chaotic Neutral
Lawful Evil
Neutral Evil
Chaotic Evil
Since it's flavor, basically, the unaligned option is saying "I'd much rather role play my character and look back on what it was rather than put it in a box and try to role play a stereotype."
Stereotypes can be, for some people, a very strong starting point in trying to play their character how they envision them, while at the same time, being unaligned can free people up to not have people stereotype them and say it's uncharacteristic of their character.
Ultimately, I think it's the best of two worlds. Since you'll have the option of doing any of the 9 alignments or unaligned, whatever floats your boat.