Why do DPS not use Limit Break anymore?

[Dirwen]

When a caster dps I prefer to use my LB on a large pull of trash mobs personally. I always use it if a melee doesn't use it on the boss.

This is what I do when I'm on leveling caster jobs. I stopped using LB on melee dps jobs when I see a caster or brd in party but nope. Bosses in low leveling dungeons are so easy to kill that I don't see the point of using LB on them anymore.