One could make equally plausible argument that random mind from the space of the minds that are not self destructive, yet capable of self improvement (which implies considerably broad definition of self) is almost certainly friendly as it would implement the simplest goal system which permits self improvements and forbids self harm, implying likely rather broad and not very specific definition of self harm that would likely include harm to all life.
"Almost certainly"? "likely"? The scenario you describe sounds pretty far-fetched, I don't see why such a system would care for all life. You're talking about what you could make a plausible argument for, not what you actually believe, right?
Why would a system care for itself? If it cares about reaching goal G, then an intermediate goal is preserving the existence of agents that are trying to reach goal G, i.e. itself. So even if a system doesn't start out caring about it's preservation, nearly any goal will imply self-preservation as a useful subgoal. There is no comparable mechanism that would bring up "preservation of all life" as a subgoal.
Also, other living things are a major source of unpredictability, and the more unpredictable the environment, the harder it is to reach goals (humans are especially likely to screw things up in unpredictable ways). So if an agent has goals that aren't directly about life, it seems that "exterminate all life" would be a useful subgoal.
You don't know how much do you privilege a hypothesis by picking the arbitrary unbounded goal G out of goals that we humans easily define using English language. It is very easy to say 'maximize the paperclips or something' - it is very hard to formally define what paperclips are even without any run-time constraints, and it's very dubious that you can forbid solutions similar to those that a Soviet factory would employ if it was tasked with maximization of paperclip output (a lot of very tiny paperclips, or just falsified numbers for the outputs, or makin...
Here's my draft document Concepts are Difficult, and Unfriendliness is the Default. (Google Docs, commenting enabled.) Despite the name, it's still informal and would need a lot more references, but it could be written up to a proper paper if people felt that the reasoning was solid.
Here's my introduction:
And here's my conclusion:
For the actual argumentation defending the various premises, see the linked document. I have a feeling that there are still several conceptual distinctions that I should be making but am not, but I figured that the easiest way to find the problems would be to have people tell me what points they find unclear or disagreeable.