Yes, I've read some Kurzweil. No, I didn't say Nietzsche was a transhumanist. He was more like a proto-transhumanist.

The question I raise here is whether transhumanists can sustain their optimism about human nature while still proclaiming that we're in for a radical transformation of our nature for the better. That looks like an internal inconsistency.

Possibly the optimism is a case of salesmanship or messaging. If something's not broken, why does it have to be fixed or radically improved?