Except they were explained, and not by Leviathan. The starchild AI explains it in the base game, as I recall, being robots designed to kill organics before robots kill organics. And I feel, *subjectively*, Sovereign spouts literally nothing but bullshit. He sounds like trump. 

"Hey, look at us. We're better than you. You can't even comprehend. Believe me, you can't. I know it, you don't know it, everybody doesn't know it." 

But I think it's connected, because I feel Bioware wrote themselves into a corner, because holy shit everyone already gives people shit when they don't treat antagonists with enough nuance like Witcher 3 does with Le Wifebeater Baron, and if you don't explain the motives of the villain/s, you're going to have people crying foul over a lack of closure. 

but that's what [i]I[/i] think.