Great White sharks are eating machines, not killing machines. Of course, things tend to die in the process of being eaten, but they aren't looking to murder humans. They are looking to feed.

And it just so happens that they have a giant mouth full of a zillion teeth, so when they go to taste you and see if you are anything tasty, they rip off a leg.

And we know they don't really want to eat you in part because of the relatively high percentage of stories that end with "And then my leg washed up on shore three days later."

So the Great White isn't a murderous killing machine. It is a callous, heartless Cthuloid Horror that doesn't give a damn about you at all and often doesn't so much as deign to swallow the arm or leg they ripped off while wondering if you were a seal.

This is why we fixate on them and make horror movies about them and so forth. If they were actually killing machines who liked eating people, we just wouldn't go in the water at beaches because the incidence of shark attacks is actually so remarkably low precisely because we aren't what they really want to eat. If they really liked feeding on "land food," the incidence of shark attacks on humans would be so high that people just wouldn't go in the water -- because it is shockingly common for there to be sharks nearby in the waters of a crowded beach and they just aren't chomping on people.