User blog comment:The Milkman/No Love For Leviathan?/@comment-4947725-20120918053701/@comment-24174486-20120918204346

Rannoch doesn't say that organics vs. synthetics (or the belief of such a conflict being inevitable) is the cause of the Reaper cycles, but it does crush the argument that the theme of organics vs. synthetics is absent in ME3. The Reapers' taunts of being our "salvation through destruction" builds up to the relevation at the end.

And to say that Rannoch disproves the Catalyst's stance is a bit of a poor argument because a peaceful resolution isn't guaranteed. The outcome of siding with the geth over the quarians definitely lends weight to the Catalyst's stance.