Debuffs never worked on fights that mattered anyways. And making them really powerful makes whatever class that uses them OP. Quite a conundrum. Pairing debuffs with damage spells/abilities makes it so even if you fail at the debuff you did SOMETHING. It's much better IMO.

Anyways we can still debuff with alchemy potions. This would be a nice way to bring Alchemy back as a viable craft, although it remains to be seen how they are intending to revamp the class.