I do not think they make that case well at all. If you look at what happened with the last generation of consoles, everything but the PS3 had piracy before anyone had unsigned code running. They ignored basically all of the security measures the consoles had implemented and attacked the optical drives firmware (with or without a modchip) and enabled 'backups'/piracy. That basically leaves the PS3 as the one that had linux so the 'real hackers' were not working on it.

The PS3 itself is still not a good example of holding up against piracy until the hackers that wanted to run linux worked on it. It was first broken for the reasons of piracy (PSJailbreak) and was not done by the homebrew scene. Actually, all of their work required and is based on already having code running on the PS3 using the pirate method.

So, what exactly is left to support the opinion that the homebrew people are smart, the piracy people are dumb, and if you do not support linux the homebrew people will make it work with the side effect of allowing piracy? In every instance it is piracy that was first. You can also look to the DVD/HDDVD/BluRay scene and see that the piracy people were ahead of the 'make it play on linux' crowd and quite capable.