(Written in September 2007)
Often when somebody asks me a question based on the word "why", be it "Why is the world like such-and-such," "Why did such-and-such an event happen,", or "Why did you do such-and-such a thing," I find myself giving an utterly nominal answer (e.g. "Because I thought it was a good idea") or a wisecrack answer (as the situation allows) that doesn't really answer the question. Like most of the time when I behave in this way, it's not just me being troublesome - there's a principle behind the action, even if it's not apparent to the listener, or me for that matter, at the time.
Given any "why" question, considering the history of the universe, there is a nigh-infinite selection of circumstances which, if any had been reversed, would directuly result in the reversal of the object of the question, and each of these circumstances is a correct answer to the question. That is to say, any "why" question has an excessive amount of technically correct answers; there are an excessive number of past events or states that could be considered reasons.
What saves the question from being completely useless, is the ability of the listener to infer which reason the asker is interested in. Given casual circumstances, in which the conversants know each other well, or where communication is quick enough to trivially correct misunderstandings, "why" is a reasonable shortcut; in long-distance communication between mere acquaintances, it is not. It is likely that much time and confusion could be saved by using more specific forms for such questions.
When communication starts to break down, it can help to use a logical mode - abandon trying to communicate through inference and construct statements based purely on their literal meaning. One has to find alternatives to the word "why" here; "Why" is not a logical question, because it relies on inference.
Solutions are difficult; after all, we wouldn't have the word "why" if it wasn't an incredible convenience over the alternatives. Huh, I actually can't think of any general solutions just now! If you can come up with anything (or have something else to say about this), please e-mail me.