Useful aspects of Alignment in D&DN

[Campbell]

I don't find alignment to be all that useful of a shorthand for a character's ethical stances. Something akin to Burning Wheel's short statements about belief will usually tell me much more valuable/interesting information about how the character sees the world.

 

[Li Shenron]

1) It is a short-hand tool for the DM to describe the broad values of an NPC.
2) Likewise, it is a short-hand tool players use to signal to the DM how they want to play their characters. The DM can take this into consideration as they plan adventures.
3) The player has written down confirmation of their character's standing.
4) It sets the scene for Spells and effects to interact with aligned PC/NPCs in appropriate ways.

Number 4) is the critical point... if you have spells interacting with alignment then you need alignment in the game.

But if you avoid those, alignment remains a useful tool for those who like it (points 1, 2, 3 remain valid!) without becoming a necessity for those who don't.

Hence IMHO it is much better to avoid such spells in the core rules. Not to mention that this allows each group to use the alignment system they prefer, be it the classic 9-alignments grid, the 4e standard, the old 3-alignment standard, M:tG colours, an honor/reputation system or whatever.