The bad code it produces is not just stylistically bad, it often doesn't solve the problem.

It seems to be making the same kind of errors in code as we've seen in speech, you get a lot of plausible but subtly wrong hallucinated content that only someone who knows the subject can identify. It prefers probable output over matching the specifications so it'll add unnecessary branches just because it's seen them millions of times.

Among errors I've seen it make there is bad indexing, adding conditions that serve no purpose or assuming a variable has a specific structure when it doesn't.