Nobody likes the word Nerf...well except for the Nerf company that makes those products. Moorgard answers an upset poster and explains why things are nerfed to create balance. Moorgard states:

First, balancing upward creates a spiral that never ends. Say a new necromancer ability is put into the game that makes the class far more powerful than intended. Because nerfs aren't allowed, you have to increase at least one ability for every other class to even things out. But now that all players are as a whole much more powerful, you need to increase NPC hitpoints and/or damage output to compensate. You must do this every single time you find an ability that is overpowered. Not only does this approach require significantly more work (instead of changing one variable, you're likely changing hundreds), but it introduces additional potential for imbalances which must then be addressed through another round of upscaling all your numbers. Hopefully you can see how this approach quickly inflates numbers in the game to ridiculous levels.

This was definetly an interesting read although I have to wonder why the poster he answered felt that something so simple had been overlooked before. Read the original post here.