There is one person in this thread that has actually seen the bigger picture. Not enough magic DDs.

Bards play paeon for melee because they run out of tp in end game fights. We all know that. Bards don't play ballad because there aren't enough caster DDs to warrant ballad. The problem isn't that Summoner runs out MP. It is that there aren't enough caster jobs that function like the rest of DDs in the game. Black mage is stupidly simple and it makes a horrible tool to compare to. They nerfed Ninja's TP management because it could basically go forever and yet there is a job designed around not having to manage it's resources.

If melee didn't rely on bards to play paeon, they would have to manage their TP and sacrifice dps just like Summoner currently does. So stop trying to get Summoner to have an infinite pool. We don't need more Blm-esque jobs. Ask for more casters jobs so that ballad will actually get sung.