This is a contradiction: "adding robots to ourselves until there is no human left", "the new AI would be compassionate towards humans."

If we use people as the foundation for building AI which eventually abandons all human foundation, then the result would not be human. It's as if you had a car and every day replaced a single part with the part for a different car. In the end, the original car would no longer exist, even though there was, as it were, a continuous camera shot of the transformation.

This is a tangent, I admit, but the contradiction needs resolved.