I think you are getting confused with the format for the reader. Someone looking for a light read would prefer a entertaining read with the twist of learning something, someone looking to learn something will be annoyed at your prose and narration style. What you write is aimed, whenever you like it or not, to a person in a particular state of mind. The motivated to learn will want you to not tell them about your grandma when they are reading the stupid recipe.
I think that's a factor as well. If the reader has a specific goal in mind, and your blog post presents itself as a way for the reader to satisfy their goal, then the reader will probably have less patience for stories.
But to take Spolsky's "Things You Should Never Do" as an example, obviously nobody's Googling, "things to never do," clicking Joel's article, and then getting annoyed at Joel for not telling them immediately. They're finding the post on HN, RSS readers, forums, etc., where they didn't have a specific goal in mind beyond learning/entertainment, so the author has more room to take their time.
