Maybe it's nostalgia talking, but I loved how debuffs actually made a difference in FFXI. In other MMORPGs I've played since FFXI, I've struggled to chose a class. But with FFXI I knew right away. I was drawn to the class for both its aesthetics and its mechanics. The jack of all trades with a pimping hat and sexy tights, Red Mage was so badass. I knew from the start it would be my main class.
But it wasn't until end game that I realized what a good choice I had made. Regular parties and mana burn parties both wanted me for the essential buff, refresh. But debuffs were also in demand. Gravity was useful for kiting HNMs, fast cast plus stun spam was useful in all kinds of situations, and even the less glamorous debuffs, paralyze, slow, poison and blind, often made a big difference in exp parties.
Because of the way parties worked in FFXI, debuffs actually significantly reduced the number of hits your tank would take, thus saving the healer's mana (or even allowing me to be the main healer), thus making you level faster. Part of me really loved how this kind of thing just happened in the background, without much thanks. But another part of me resented how the Ninja got praised for using utsusemi so well, when it was really my paralyze and slow that enabled him to use his shadows so effectively.
I recently started playing Bravely Default, and seeing the same old debuff spells (in a game where they are, even more than usual, clearly worthless) reminds me of Egoraptor's Castlevania 4 Sequelitis episode. Often sequels will carry on a game mechanic even if it has become obsolete. The funny thing is, debuffs have always been obsolete in FF games, the only game that managed to make them useful was FFXI. In offline games debuffs don't land on most bosses and most trash enemies die before the debuff makes much of a difference. With the Brave/Default system introduced in this game, trash mobs have become less than trash, they are dirt. When every member of your party can attack 4 times from the first turn, why would I ever bother to debuff?
I've only just started the game, so perhaps I will be proven wrong, but I doubt it. When you can plow through enemies with brave attacks, debuffs seem like a huge waste of time. I don't think vestigial mechanics from prequels are all that bad, but I do wonder how they could've been changed or updated to better suit the new game.