"I delete off topic and impolite posts. Questions and comments about the article are welcome. Personal disagreements with the author are not."
This is not off-topic, impolite or due to a "personal" disagreement.
The reference to his other work is not off-topic because it reflects that this is not the first time the author's expertise has been questioned through reader response to his work. Many of the statements in these two articles are blatantly false and should not attempted to be passed along as anything else.
I guess a new question comes to mind...how many times will oreillynet.com support articles/books from a particular author whose expertise is continually questioned by readers before it is suggested that he be a little more professional?