The author clearly means professional publishers, who have editors and fact-checkers. Self-published books already lack trust. The reply also misses several other points the author makes, which I find ironic because it kind of goes into the direction the author bemoans: The author wrote a longer article to lay out his thoughts and it sure took him time to write and any reader time to read and digest and here is a quick oneliner as a rebuttal that took no time and effort and is superficial.