On the other hand, if they didn't put in a lot of effort to prevent the stupidest form of counterfeiting, then the stupidest form of counterfeiting would be the real problem.
I seriously doubt that this helps at all. If someone tried to print bank notes from Photoshop and fails, they'll just try some other graphics app. I'm pretty sure Gimp and many other apps will work just as well as Photoshop would have.