User blog comment:Ironreaper/Problems with the Catalyst/@comment-50.68.72.199-20120714172632

simple answer, choice. if the catalyst is the embodiment of either a)the original sentient organic race that created the reapers, or b)the minds of all the races the reapers have harvested it chooses to let "fate" decide when the cycle ends. that being said the reapers are machines that are restricted to their programmed roles, as much as their ai says otherwise. the catalyst who has the ability to control them or destroy them, simply does not. it ensures races unprepared for synthetic life dont make it. every cycle a small amount of residual knowledge is passed on, this built to the point where shep and the current cycle can and did end it.

the catalysts choice to let the cycles continue is flawed. not the idea behind its choosing inaction. the only problem i have is safe guarding evolution by forcing it to restart to be "fair" isnt following the "celestial imperative". however maybe the catalyst has deemed it acceptable to ensure the survival of organic life until organic choice and will put an end to the harvest. also makes sense why the reapers/catalyst preserve cultural identities as to not loose them to the sands of time.