Ummm have you actually read his site ?
I see nothing of commercial gain for him and the majority of it is tutorials, examples and free software to help out beginners.
Yes, nothing of commercial gain at all, and not even a hit counter - on any of my sites, not just the one in question.
The reason for it been in my signature is that the tutorials were written basically to answer a great many of the PIC related questions on here - and I got tired of continually retyping the answers.
As for actual 'commercial' links in posts or signatures, I only allow them for proven valuable members - anyone posting here just for advertising purposes is deleted and banned.