It's uncharitable because the comment purports to summarise the entire paper while simply cherry picking the worst result. It would be like if asked how did I do on my test and you said well you got question 1 wrong and then didn't elaborate.
Now I get your point that a function that is 99.7% accurate will eventually always be incorrect but that's not what the comment said.
I just tried to get to the heart of the claim based on a skim. Please feel free to refine my summary.