Truthfully I'm just echoing hearsay, I've no empirical data to back it up. I imagine the crux of it is largely TP related even if it's higher PPS, as not only is Fracture less of a DPS increase for PLD now than it was in 2.0 but you also don't have access to the plethora of free TP generated from GCD Shield Swipe. It might still have uses regardless, like in A5S when running away for Boost while only being able to do Fast Blade or Fracture.