Healer LB3 is terrible, and it's rare that it actually saves anyone since it not only causes the caster to be rooted for several seconds but raises party members exactly where they fell, even if they happened to die in the deep end of an instant kill zone.

Besides, DPS LB is a key part of most progression strategies, meaning that if your party isn't overgeared for the content or doesn't play flawlessly, sacrificing the DPS LB is as good as ensuring a wipe if the group struggles at all to meet a tight DPS check.