The author of this quote is implying that the more you reuse your public address, the easier it becomes to generate the private key from the public key. The author seems to be implying there is a flaw with the RNG (I assume your reply assumes the RNG is not flawed). Is there a flaw with the author's quote above?
No. He's correct.
You got the meaning wrong however. My reply does assume that the RNG is flawed(in a poorly implemented wallet). The point with that sort of attack is that an attacker can easily get your private key using at least two signatures that reuses the R value. If the wallet is flawed, the values could potentially be the same and address reuse does mitigate this since each address would only have one output that would be spent and the address would only be used once.