It's hard for you to be wrong. If someone with zero programming talent does become really good, you could just say that they did have talent after all.
Let's make a baseball analogy. Do you think a person with no hand-eye coordination can become a great hitter?
I have no doubt there are people who are math averse who have plenty of untapped math ability (e.g. most women with math ability have been taught to think they can't do math). There are plenty of psychological reasons why a person who is capable of doing something might think they have "zero talent", and it's perfectly plausible for a good mentor to help them unlock their ability. But that's a far cry from the argument that "anyone can be a great programmer".
I have no doubt there are people who are math averse who have plenty of untapped math ability (e.g. most women with math ability have been taught to think they can't do math). There are plenty of psychological reasons why a person who is capable of doing something might think they have "zero talent", and it's perfectly plausible for a good mentor to help them unlock their ability. But that's a far cry from the argument that "anyone can be a great programmer".