I also don't understand why they have linked the number of ED points to the number of PLs we have. The benefit of epic PL is very good, epic grind didn't need an additional incentive. It was a mistake on their part not to give all the points regardless of the number of PL we have.
My bet is if they created the system in isolation they probably would not of but they created the system with the baggage of the old system that let you have all the power at level 20 after you unlocked it first time and epic PLs was tied to twist of fates. To not make it seem like anyone that grinded for twist of fates wasted there time they moved that progress toward the perm Destiney points system and the perm Destiney point system was there as a compromise so there was still a big boost in power at level 20 even if it was not as big as the old system.
I do agree that the one change that would reduce the time it take to get the majority of the power in the past life system would be to front load racial AP's. This will put it more in align with other systems like first 12 epic past lives to get your 4 stances give the most power, Heroic past lives for most part fairly minor to any build so can just pick and choose, Iconic first 3 for the stance you want give most power, Reaper I would say the vast majority of power is in first 84 reaper points so 7,056,000. Going from that too 24,336,00 for 156 in most builds come down to more HP, there may be some exception like maybe a melee warlock where maxing MP and SP matters but for most part you in good shape going deep in 2 trees.
Then you got racial action points where you can make a augment that going from 5 to 6 give less power then going 11 to 12 and that less then going 15-16. On top of that you only get one every 3 lives make this a extremely backloaded system unlike any of the other exp grinds.
My personal take on grind is if the goal is just the achievement of getting every past lives then I really don't think reducing the grind is needed but if the goal is to get new players at a reasonable pace so they can use the same builds end players uses then some grind reduction is needed and simply changing the racial past life grind to be front loaded would achieve that.
On the Destiney points being tied to epic past lives this can be a issue but for most part I not seen many builds where having a few less Destiney points totally break it but on other hand lacking the racial AP appears to me to have a much bigger impact on weather certain builds will even work.