Comment by ben_w

They explicitly said so, phrasing it as "laziness", on their blog post.

"""Today, we are releasing an updated GPT-4 Turbo preview model, gpt-4-0125-preview. This model completes tasks like code generation more thoroughly than the previous preview model and is intended to reduce cases of “laziness” where the model doesn’t complete a task. The new model also includes the fix for the bug impacting non-English UTF-8 generations.""" - https://openai.com/blog/new-embedding-models-and-api-updates