Why is gearscore used only on WOLK realms?

[WolfCD]

Gearscore is used everywhere in woltk, yet no where else. Why is it so popular in woltk and why only there?

[Valican]

Gearscore is used everywhere in woltk, yet no where else. Why is it so popular in woltk and why only there?

Because WotLK was the first to really introduce the idea of gear levels. Before in Vanilla/TBC IIRC... it was just tier level gear. "I have MC/Tier1, but no BWL/Tier2" etc. GearScore was scrapped after Wrath during Cata which swapped to Item Level instead.