Bad humans ?
Or maybe remembering a bunch of things that are intentionally hard to guess just isn't a very good way for humans to authenticate themselves ?
It's often a good idea to match the solution to the problem : if you need to do a thing often, choose something that you're good at.
What are humans good at remembering? Probably something involving patterns. Shapes, music, phrases. The problem there is that to enter a reasonably complex pattern, you need an interface that's good at it. Maybe that's easier to solve than trying to make your passwords rememberable but obscure.
Biting the hand that feeds IT
