Originally Posted by
Gadix
Stat weights were usually normalized to PP in BC content, because spellpower was the only stat we really wanted. Everything else was a fraction of spellpower's worth, so it made sense to represent them in terms of .2 spellpower for easy eyeballing of gear.
More to the point, normalizing your stats doesn't in any case mean that they don't change. When haste is better than SP (and it is at certain gear points), if you normalize to SP then it just means that haste has a value greater than one. I personally prefer to just know how much dps I gain from an upgrade, not the dps gain divided by some arbitrary number.