Bards are arguably the highest single target dps in the game.
Bards have extremely high burst (probably the highest, but BLMs are pretty close?)
Bards are the most mobile dps class in the game.
Bards have the best utility in the game (songs, silence, root, slow)

Give us a stun and a dps limit break and we won't need to bring any other classes to anything. Maybe a BLM for AoE once in awhile..