I don't think he said that at all. The point is that writers who have made the mistake of plagiarizing unintentionally have seen careers destroyed for what they have done. These are people who have long shown that they are capable for developing their own ideas and stories, and have mistakenly reproduced something that was not their own as their own. Even though they fess up to it, they are villified - and the proof of innocence is buried on page 15.
There was also no assertion that she is talentless (although, I think she is). But, there is an assertion that faith should not have been placed in her. Even if the publisher had faith, $500,000 worth of faith is a lot. This isn't the MLB, professional soccer, or the NBA where you sign a kid out of HS based on potential (but it is silly that they do it). If the writer is a rookie - you pay them based on what they sell. If they have proven themselves as writers or a name that people will buy (see: WJC and his $20m advance), then you deliver an advance. And I think the thought that the advance played a part her doing what she did is a reasonable one. Are you saying that you wouldn't be tempted to do whatever you needed to keep the $500k? I mean, if the original author was that inspirational, she should know those books better than any other. I know exactly when I begin to sound like Roald Dahl in my writing...
And the amount of money that she is making off of this (advance plus whatever else she earns) should be used to repay the author she stole from. To admit she made a mistake and keep the benefits? I guarantee that when I was a kid not too long ago, if I stole something, my parents would have knocked me silly if I didn't give the item back. There is not a single person on this planet (or any other) who should keep the benefit after stealing.