Metaphysical sophistry about souls notwithstanding, that is exactly how Rejoinings work.
It's been acknowledged and the story portrays it as a necessary evil. Shouldn't need to be repeated ad nauseam.
More pointedly Venat's main objection was that the Ancients were willing to sacrifice themselves and new life, and the infinite possibility that comes with the future, for the sake of a past that never was and never will be. The "perfect paradise, free from sorrow" the Ancients wanted back never existed to begin with; they were just looking back with rose-tinted glasses (seems to be a worrying issue with Ancients in general) and unwilling (or perhaps unable) to cope with traumatic loss because their relatively carefree lives of peace and contentment were upset for the first time anyone could remember. More pertinently, Zodiark was an irresistible temptation to achieve that rose-tinted "perfect" past because with enough input he could actually make that... but would the cost be worth the sacrifice? And I'm not talking about aether.