First, before I do any granting, what? O_o "The crocodile's bite force is more than 5,000 pounds per square inch,[3] compared to just 335 psi for a rottweiler, 400 psi for a large great white shark, or 800 to 1,000 psi for a hyena."
That's closing. The muscles that open a crocodile's mouth are so weak that you can stop them by a putting a rubber band around its head.
I still wouldn't call that a weak jaw though. That's like saying a chainsaw sucks because you can't make a tree grow with it in the same time you could cut one down. Some things have specialized functions.