Actually I think that's probably the only "good" thing about this punitive damage cap. By declaring that there exists a cap, you create a constraint for the jury, so they may end up deciding on a smaller punitive damage because of the cap.

Instead, allowing jurors to decide on a larger punitive damage than the cap can have a symbolic meaning. The court is bound by law, they can't avoid it, but the jury isn't, so whatever amount they decide is the amount that they believe reflects the severity of the crime.