> - don't directly address the point of your question / provide a much complex answer (or even worse, a non-answer) to a simple question
> - don't stay focused to the point of the discussion
I often dive deeper if the question itself raises suspicions that the question asker might not fully understand the topic. For example, if someone asked: "can you unbatch those 1k RPCs?", I might go into more detail than a "yes" or "no". I do it to spare the question asker from making a bad decision, without wanting to embarrassing them by saying that the question is too simplistic, or makes no sense.
> - don't some level of clarity in their train of thought and speech
You yourself are missing words in your communication like the word "have" in the quote above. Also, I don't know enough linguistic rules to correct you, but colloquially at least your title is better understood if you write it as "Why do some people not communicate clearly?" So some compassion when others misspeak might be good. Often it's possible to read between the lines.
> - generally over-complicate matters by wandering off to other related subjects and extending the scope of the discussion
Creativity is often the expansion of a topic, or the merger of multiple topics. Maybe your question sparked their creativity and they're taking the opportunity to show you some of their creative thought process.