The owner XboxAchievements.com and PlaystationTrophies.org, Dan Webb, was interviewed on the DRM Gamecast and the topic of DLC without achievements and Destiny were brought up. He thinks the idea is ridiculous and even offers to make the achievements for Bungie! You can listen to the episode here (The Destiny talk begins at the 1hour and 4 minute mark): http://www.drmgamecast.com/2014/12/drm-gamecast-ep20-world-wide-webb.html#more