No, didn't play Leviathan--kind of got sick of the original story because of sci-fi tropes like this (not talking about the ending). OK so reapers were programmed to preserve life at any cost, but how much?After the first reaper, they could claim their mission is done. No matter what happens in the galaxy, as long as that reaper survives, organic life has been preserved. Why do it every single 50k year cycle? What's the point?
I don't follow. Are you asking why they don't just "reaperfy" every organic race in the first place?
1. New organic races would eventually evolve. That's how all new species exist now despite much life on earth being wiped out 65 million years ago.
2. Preserving life in the form of a reaper is the last resort, end-game tactic when an organic race has become advanced enough that they're a danger to themselves and others from the synthetics they have, or will, create. As I said, the point of the reapers is, in a strange way, as a protector to let comparably primitive organics thrive until they've embraced technology to a certain point. Without reapers, the notion is for example that a random, primitive, nomadic species on some random planet would eventually become enslaved/eradicated by a far superior synthetic race created by some now extinct organic civilization elsewhere in the galaxy. The reapers' purpose is to stop this from happening.