You're discounting the rewards that Mhach offers otherwise and making it specifically about one aspect. It offers the following, as someone stated above: an i230 gear piece, some of which are actually BiS such as the Black Mage chest, yes better than the i240. A token to upgrade said i230 Lore gear to i240, a token that provides you with a free pice of Grade V materia of your choice, 100 Tomestones of Esoterics and 20 Tomestones of Lore. And of course the other chest drops like the Coffin Lid, minion, and orchestrion rolls.

It isn't all about Lore. I disagree that it is imbalanced considering the other rewards that are offered. Especially considering you listed other examples of how easy it is to get Lore.