Why is Ruin a cross class skill?

[Inuakurei]

Same reason BLM can use Hawk's Eye.

Hawk's Eye -- Increases DEX by 15% and physical accuracy by 20%.

Poor design.

I wish they'd change the description on that. It says "increases physical accuracy" but what is actually does is just increase your accuracy stat, which does help blm land status effect spells (like sleep and binds). So it's not really "physical accuracy" but just accuracy as a whole. So it is useful