Broadcom, as I understand, is as secretive as they are as a defense against patent trolling. When you have NPE's gobbling up garbage patents to sue everyone and their brother with, locking up the IP tightly is one adaptation to defend against that sort of thing. Still pisses me off to the ends of the earth.
Does the author imply that open-source advocates believe that secrecy is bad for profits and that open-source is a way to get rich? I've not personally heard that. I do recall arguments that opening your source code will not lead to financial ruin, but that still leaves open the possibility that they're uncorrelated or only weakly correlated.