He didn't say exactly that, he said that he takes issue with his manager calling him the "least effective" person on his team. Which sure, there is some possibility that he wrote a lot of code, and it was all useless, but to be the _least_ effective while _presumably_ shipping at least some features...
Either he's incredibly, incredibly bad at what he does, or he just had the misfortune to step into the bear trap that is the Amazon PIP machine.
Knowing Amazon, he probably just got unlucky.
