I hate unanswered questions, I really do.
So I was thinking now for (at least) the third time about answering "Why do writers use the tenses that they do?".
But my answer would be pretty much the same like what was answered in "How to write in past tense". No one agreed to my close vote, which is fine (and Neil tried to make it more answerable), but may I ask what makes it different from the other question? Maybe I can provide then an answer which is not repeating what was already written.