Realizing you're just joking but I'll explain it anyway.
The whole "revenge" implication is silly. In the first movie it was just a rogue shark with no motive other than hunger. It places the film less in the realm of monster movie and more in line with Halloween and Texas Chainsaw type films, which were just becoming popular around that period.
Even some of the POV camerawork when it's supposed to be the shark is stupid, because the camera will be still for various scenes, as though the shark is sitting still behind seaweed or a few 100 feet from the beach (notice the scene when Roy Scheider pulls the body from the water--are we to believe the shark is watching Brody, or is the director just being inconsistent with the visual narrative style?), waiting to strike like Jason Voorhees or Michael Myers. In the first film, the "Shark-o-vision" was usually in constant motion, so we got the sense of a beast in perpetual movement (also fits with Sharks' biological design, since they will sink if they cease swimming).
The teenagers who are harassed by the shark all fit the classic slasher movie victim archetypes (nerdy kid, practical joker, jock, whiny blonde, etc).
Not to mention the cheesy burn scars on the shark after the boat explosion.