In fairness to Kurzweil, he isn't talking about a simple chatbot. That's a pretty big difference.
But beyond that, there's an argument that there's no clear distinction between a simulation of a person and the person.
If you want to get into this, start out by telling me the difference between A) a new sorting algorithm you wrote vs B) a simulation of the new sorting algorithm. In particular, why B isn't also running the same algorithm.
If that's not an objection, there's the question about "completely equivalent to the previously alive human being" - pragmatically, it seems impossible to me to fully recreate a 'completely equivalent' human from their writing/output; but, if you're willing to accept a 'so similar you cant tell', the idea is no longer as clearly ridiculous as it first seemed to me:
How big is the space of potential human minds?
Lets say you've an incredibly powerful intelligence: its got someone's DNA and their writings/output. And lets say it has a lot of data on humans, and has deduced a pretty good model of how their minds form, given their DNA and experiences. How much can it now deduce about how a deceased person's DNA was expressed, and the person they became, given their experiences? How small is the space of minds it could narrow in to, from that data? Can it find a small enough space that another human can't tell the difference?
How hard is it to model a human mind? I can make pretty good predictions about what people I know well will say in response to many situations.
But I don't know; I don't think we know enough about minds to say one way or the other.