I suspect there are three possible reasons for this:
1) some people believe a computer can never 'think', so the question is stupid to begin with.
2) some people believe that while it might be possible for a computer to 'think', this program wasn't built to 'think', so whatever it's doing, it can't possibly be doing that
3) some people believe that while it might be possible for a computer to 'think', since this is just a 'language model', what it is doing can't be 'thinking' because 'thinking' involves something more than pattern matching
The trouble is, I'm not sure why any of these three groups are able to be so certain. It's no good saying "I know this isn't 'thought'," if you don't actually have a way to complete the sentence, "... because 'thought' is:..."
I don't believe we have any theory for what the required architecture for 'thought' is. I don't think it's been remotely proven that there's something involved in 'thought' that a sufficiently large 'language model' with a sufficiently long 'attention window' couldn't also do.
So how can anyone be so immediately sure that there is something more to it, or that even if there isn't, that this particular system isn't sufficiently large to begin to be capable of thought?
To be clear, I don't actually think in this case Google accidentally created a sentient chatbot.
But I do worry that at some point, someone might. And I'm not sure I see what, if that day comes, would lead any of these three groups to a different conclusion.