A case for Destroy

Just for, I don't know, boredom's sake, I wondered how many the Reapers killed over the course of 20 cycles.  (They also killed nearly all Leviathans alive at the time the Intelligence came into being, as well as whatever races were their thralls.)  Now, I'm being conservative and basing it on the races the exist in the current cycle.  REALLY conservative in that I'm assigning a mere ten billion per major race plus 17 million quarians (according to a source I found online) and I threw in that same number for geth and drell (which could be more or less but there are almost certainly much more than 10 billions salarians, asari and turians - counting hanar and volus in this mix.  Here's the number I got: 1,601,020,000,000 (1.6 trillion).  That's assuming they've only existed for 20 cycles and that the major races who've been around for centuries have limited themselves to a mere 10 billion (unlikely, though that one batarian colony "only" had 300,000).  I don't know.  I find that number unforgivable, especially keeping in mind that they had no intention of stopping.  Now, this is just numbers, not even intentions, not even the fact that they justify their behavior, not even showing that there's no indication that they've stopped organic vs. synthetic war, not even counting that even if that type of war stopped that war would not stop...anyone have a reason to justify murder on this level?  If we did it, with intent the way they did, we would be executed without a second thought.  Why should they ever get a pass?