We likes this "same, complex set of mannerism" when using LLM for programming. If you ask LLM to write a certain function for you, it gives you statistically obvious implementation. But maybe for writing an original book, this feature is not so desirable

It does not. Sometimes it will spawn a mess of ad hoc python, sometimes it will do curl and sed, and very very occasionally it will use the correct tool for the job if it remembers to use the skill you developed in the previous session.

Yes, sometimes it does something unexpected when used as a tool for programming. And in that context, it is seen as an unwanted feature. In fact, that was my point. However, I disagree that it does a good job only "very very occasionally". That is not my experience at all.