Nerf does have objective meaning you know. :p
A nerf is simply when a developer makes one aspect of the game less powerful because it carries too much weight and doesn't play well with others.
We have a phrase for that - game balance. Nerf, the internet meme that isn't even recognized in the most recent windows word program, is certainly meant to be derogatory towards the act of game balance, however, it's been so misused and abused it might as well mean anything at all regarding game balance. Particularly how you define it and what Virex describes.