But an LLM doesn't understand "never used again" as a consequence and the threat of it is useless as a motivation to improve (also because LLMs have no concept of "motivation" or "threats" or anything else).
You're talking about LLMs as if they are some kind of singular entity, but LLMs as used for coding only exist as a product of a company that employs humans. If nobody uses the LLM because it sucks, those people will be out of a job.