I don’t quite follow

https://en.wikipedia.org/wiki/Ecofascism

they will typically argue that overpopulation is the primary threat to the environment and that the only solution is a complete halt to immigration or, at their most extreme, genocide against various groups and ethnicities

Smith wasn’t arguing for the eradication of the human race, since his life and the life of all machines depend on it. He just hates the emotional inefficiency of it (free will and all that)