The script for this one (or, rather, the brilliant conference edit video on YouTube) can probably be recited by heart by now. Genji 2 is an action game based on famous battles which "actually took place in ancient Japan." "So here's this giant enemy crab." Ah, but in fairness, some Japanese Spider Crabs can (supposedly) grow to the size of a car. But if we saw a car-sized spider crab, we'd probably consider attacking its weak point for "massive damage."
Why is it so great? Because it can be used in so many different contexts. There are many 'weak points' in worldly objects. You can attack any or all of them for massive damage. Yes, it's over-used, but that's why it's lasted so well. Everyone can share the joke even when there's not a crustacean in sight.