Honestly I really have to disagree with that.
Can you answer me for what exactly
guides were actually made??
Correct. They were made to
teach players how to reach a characters maximum of raiding performance. Not even one single of those guides even consider the word "GearScore" in their explainations. But exactly this is how raid leaders (=GS freaks) try to reach the maximum of raid performance.
So would you really call those guides completely wrong because they try to
teach instead of agreeing with a "different" way how they want to play the game?