I have been using LLMs since August last year, and I know the output they can produce. And I know that the initial output requires refinement in most cases. And that's coming from someone experienced in Software development. LLMs in the hands of people who are not experienced lead to skip a proper review process.
Additionally, it's unreasonable to assume one can take a large codebase and will spend hours on examining the code before. It's not only unreasonable but downright ridiculous.
LLMs are a part of reality right now and they're not going away. Code should be labeled as such. Not doing that is inconsiderate.