That adds a limitation on magic. That's desirable for BHanson because it's replacing the profession's role in determining what spells a character has access to. It might be desirable in other games where you want to narrow magical access.
If you don't want to limit magic, you could still make it relevant, for example it could be used in magical research, in performing rituals (for which limitations are probably a good idea), for spell mastery, etc.
As a middle ground, it might be useful for identifying enchanted items (which might need to be marked in the appropriate language during creation), magical glyphs, wards, and symbols, stelae and other magical architecture, for identifying and using runes, and for learning spells from grimoires. The appropriate language might be spoken by very highly magical creatures tied to the appropriate forms of magic. Even if items are not marked in actual writing, a detection/study spell might force magic to manifest as language which the caster then needs to interpret. That language might be clear or it might be full of metaphor and poetic vagueness. ("Ok, I think I understand a carpet that sails like a ship upon the clouds, but what is a wand that is full of summer's grace?")