Well I disagree,
The way I see it, Its the only way to bring on Legendary versions of named items from Epic level gear.
Without Legendary challenge to earn Legendary gear or upgrade tokens, it would be asinine to allow a 25 token upgrade to upgrade level 20 epic gear to level 30 worthy gear, while farming level 20 content on level 30 toons.
but hey I have 800 greater tokens across my toons just sitting around collecting dust.. that's 32 upgraded Epic items for nothing..