There is a huge difference between what a bard can do and other classes can do. The closest thing is the piercing and slashing resist down because they work for more than one job, but neither of those can hold a candle to ballad or requiem --both of these are disgustingly strong. Paeon is [largely] useless, but in one or two spots it can make an entire strategy go more smoothly.

Notice most of the things you bring up debuff the mob, not empower the party. Empowering the party is what support does.

Support vs. Enfeeble, not that we have an enfeebling job because everyone has a little bit of that pie.