Originally Posted by
Bladesyphon
This is a very incorrect argument when used within the MMO Genre. In a Single Player game that is more balanced around skill than gear, yes, gamers change over time by improving. A player that is unable to defeat a boss in Dark Souls would, in theory, be able to defeat the boss after a number of attempts as individually he is becoming better at the game with each attempt.
In an MMO, especially one like WoW that is heavily gear heavy, this same principle rarely replies. Just because I can handle the mechanics or gear check of a boss does not mean everyone else in the raid can. That means that I won't be able to progress without leaving my raid for another, or waiting for the others to catch up, if ever.
This is why the nerfs are implemented: So players can continue to raid with an established guild of friends without feeling like they have to leave them for a guild that's more capable of clearing the content.