A society of EMs start from a human basis. So we have a better idea of their weakness and they have a better idea of what we mean. They also have specifically human failings.
An AI made ex-nihilo can be, potentially, in a much greater area of mind space. The failure modes for the AI are likely to be quite different (eg we don't need to worry so much about them being corrupt, but a lot more about them misinterpreting what we mean).
They could be identical in practice, but it's still worthwhile separating the two conceptually for the moment.
Toy model of an upload-based AI that doesn't seem to suffer too many of the usual flaws:
Find an ethical smart scientist (a Gandhi-Einstein), upload them, and then run them at ultra high speed, with the mission of taking over the world/bringing friendliness to it. Every hour of subjective time, they get reset to their initial specifications. They can pass any information to their resetted version (limiting the format of that info to a virtual book or library, rather than anything more complicated).