Why? Just because he is no longer using it for business purposes doesn't mean it isn't still perfect for what it was designed to do, blogging.
I think he means if you are going to hate, hate on it all the way.
"I love WordPress. With it, I have felt a genuine affinity for a product the likes of which is matched only by my Commodore64."
Who's hating?
>"It will be exceptionally strange for me to no longer recommend WordPress."
So presumably this is hyperbole and you'd still recommend it, only for a more limited range of sites.
The big question, as others have said I think, is what do you now recommend?
While I disagree with the author, he acknowledges that WP is good for blogging. He's arguing that it's not suitable as a general purpose CMS (for his clients).