The primary point of distinction that allows AI generation to be inferred appears to be that the code is clean and well-structured. (Leave aside for a moment the oddity that this is all machines whose primary benchmarks are human-generated code written in a style that is now deemed too perfect to have been written by people.)

Does that provide an incentive for people writing manually to write worse code, structured badly, as proof that they didn't use AI to generate their code?

Is there now a disincentive for writing good code with good comments?