I won't call a film a ripoff unless it adds nothing to the world which wasn't given by the original.
Pi clears this bar easily. Sure, shooting 16mm off the hand, with oversaturated, Expressionist lighting, and some of the body horror (or did they both "rip off" Cronenberg there?) approaches homage. If one has seen Tetsuo first, there's more to appreciate.
But Pi is an excellent movie, which carries its own themes gracefully, Aronofsky made his reputation on that film and deserved to. The soundtrack was also groundbreaking.
If we were to adopt your idea of what constitutes a ripoff, the result would be more bland and defensive cinema, the kind where the script may as well have been written by the studio's attorneys.
From reading the synopsis of the plot (I've seen Pi several times, but never heard of Tetsuo: the Iron Man before), what does Tetsuo: the Iron Man have to do with Pi? The story at least shows no obvious connection.
It's a question of degree, and also one of context. In this case, he seems to have extracted a lot of value from somebody else's work without himself having created much that is new.
Pi clears this bar easily. Sure, shooting 16mm off the hand, with oversaturated, Expressionist lighting, and some of the body horror (or did they both "rip off" Cronenberg there?) approaches homage. If one has seen Tetsuo first, there's more to appreciate.
But Pi is an excellent movie, which carries its own themes gracefully, Aronofsky made his reputation on that film and deserved to. The soundtrack was also groundbreaking.
If we were to adopt your idea of what constitutes a ripoff, the result would be more bland and defensive cinema, the kind where the script may as well have been written by the studio's attorneys.
So let's not.