If you want a tutorial how to connect a serial and execute John the Ripper, you should definitely click that link. Otherwise you should stay away from that obvious clickbait.
it depends on the size of the wrench
Linux has never been intended to be secure against someone who has physical access to the hardware.
Hi I did not meen it to be clickbate. I wanted to show that unles you have the router in your hands it is hard to get in to a OpenWrt router.
As any data processing device without encrypted storage
The article does not show how hard it is to break into an OpenWrt router. For example, they could run any penetration tool and show how OpenWrt resisted all attempts.
The article shows how easy it is to break into an OpenWrt device, once you can lay your hands on it and connect by serial.
So, the title of this post may have been interpreted as ironic, and hence the "clickbait" complaint. I think this is just a misunderstanding.