User blog comment:LilyheartsLightning/Citadel and Reckoning DLC announced/@comment-737801-20130221183242/@comment-1440333-20130222022255

Then what is the point of weapon packs, or appearance packs? They add nothing to the story. The point is that its fun, allows an extra immersion option for the game, and promotes the replay value of the game, along with the weekly challenges.

Also this - All the multiplayer dlc does is give you the occasional new enemy, new locales, and new tools to kill those enemies

- could also be used to describe Omega, Arrival, Overlord, etc when you boil it down. The story for the multiplayer is established in the main game, as well as the blurbs announcing the new events, or failing that why not create your own headcanon. I do, and Im sure Im not the only one. The reason why I disregarded it in the comparison is because, just like Zaeed and Firewalker, it is free - meaning any player can get it, meaning that it counts as part of the main game, not DLC.