People like things to be subtle though.
They can also read into things that aren't there.
I offered to help someone the other day in a comment (which I did - then going back and forth with several emails and advice which took time) and was voted down in the one line offer. I guess they looked at my profile and thought I was angling for paid work? The truth is I've helped many people but never asked for payment (although it's been offered.)
To which I say "chicken dinner"!
Disclaimer: I worked with Steve. He obviously has a nose for marketing, pr all that stuff. So of course he will always be angling for anything that will raise his profile. Which is, as you said "not to say that the books and programs aren't necessarily good".