There are guys out there making a lot of money peddling stuff that looks good but may not be all that practical. I attended on seminar where the 'master' kept pulling me out to demonstrate. Nothing he tried did what he expected it to do and he was hitting hard. He then labeled me a 'non- responder'. As a result I would never use or teach the use of strikes to those points. Against a 'non-responder' with a weapon you get one shot at it. If you are relying on a point that may or may not work the way you intended then you are neck deep in it.Now, that said, "pressure points" (I'm not personally fond of that term) do work. Not all of them work as advertised, and not all of them work on all people, but they certainly exist. I prefer to think of them as "vulnerable points," and that includes all kinds of biological structures that are particularly vulnerable to negative stimuli.
In Okinawa I tried to learn something of kyusho from the top guys we were training with. They denied knowledge of it although I would be almost certain they were training kyusho at their level. It wasn't until I met Hokama Sensei that anyone would talk about it.
Thanks for the link to your friends article. It was very interesting.