In the story:
Yes, to make someone not judge, they make them give up their memories.
The suggestion is that there wasn’t control of access.
You couldn’t convince most to go through the process if the memories were destroyed.
However, the value of a memory is destroyed if it is removed from its setting, context, and history. Doesn’t matter if they go back and view them, they have no emotional value, nor do they convey any lessons. This was reinforced with:
Uther the Lightbringer says: No. They serve as a reminder of lessons learned. Given the choice, I would never let them go.
In function, the memory process on the Path was an anima harvest. Sure it had an excuse, but it was mostly about anima.
The story has now junked it by saying it was without compassion. (Great, awesome, how many generations of people, from how many places, got sent to Bastion when it didn’t have compassion? Way to think ahead.)
As the original Path required giving up memories to ascend, there was no choice; it was false-choice. (Hobson’s Choice.)
As far as choosing to leave the Kyrian: I think this ends up being a false-choice once memory removal has already happened. How does one decide not to be Kyrian when you no longer have the faculty provided by memory based experience? There is no foundation for it.
That’s leaving aside the mess the Forsworn plot left us in; they didn’t get to leave, now did they. It took compassion to see the Path had a problem, not just letting bygones be bygones.
There is a story hole: How did the Arbiter send someone to Bastion because it was right for them, but every single one wasn’t actually ready for Bastion when they arrived? When 100% of them had to go through a process and purge themselves, they, by definition, were not ready for Bastion!
The very claim that memory purging prevented bias means that people who came could be seen as being biased before being purged.
That is a concept trap: They were not the noblest and purest souls, they were just like other souls; subject to the lesser emotions that would need to be purged.
Outside the story:
The writers applied the concept of needing to purge the self entirely. (Bad concept TBH.)
They wanted a story arc to expound the Forsworn, and got it from the same thing. It was a simple vehicle for Lysonia and Devos’ plot to have their memories floating around.
Their view of this memory stuff is likely to also be what is floating around in their minds because of Sylvanas.