Rhialto, on 16 March 2014 - 06:43 PM, said:
My guess is because they hope to encourage people to play more and grind for achievements. If they were to reward retroactive achievements to the players who have been around since the beginning, the system wouldn't be doing anything to motivate those people to play. Of course that assumes that a significant portion of those players actually care about achievements to begin with, which is debatable. I have never been a fan of achievement systems that reward completely arbitrary accomplishments rather than achieving actual game goals.