People used to make the distinction as a matter of being correct, not elegant.
I like to think of it this way:
There are three broad basic functions performed by verbs in sentences; they express one of three things: action; existence; possession.
1. Action - "I eat breakfast"
2. Existence - "There is an egg on my plate"
3. Possession - "I have a book"
Now, consider that the action class expresses what one does and that consequently the concept of "do" is inherent in all verbs of this class. Action verbs contain two elements: the concept of "do" and something else that tells us the precise nature of what is done. We can see this clearly when we switch from a simple statement to a question: "What do you eat for breakfast?" In the case of questions in English, we invert word order. For action verbs, though, English has come to extract, insert, and invert the concept of "do". The SVO of "I eat eggs" becomes OVS(V) "What do you eat?" when the object is unknown or VS(V)O "Do you eat eggs?" when it is known. We effectively split the verb into two parts. Notice that where the tense changes, only the "do" portion is modified. "Did you eat eggs?"
Consider simple existence: "This is a pen" There is no action and hence no "do" contained in the modal verbs (forms of "be") and modal verbs also don't take objects (Which is why things like "It is I" used to be the educated ideal, instead of the currently universally MISused "It is me" ("me" is objective case)). So when we invert we get "What is this?" instead of "What does this is?" which is what we'd get if we followed the pattern for action verbs.
Now comes the problem....
In the case of possession....the concept of "have"....there is NO action inherent as is the case with verbs in the first class mentioned. Hence, there is no concept of "do" inherent in "have". Therefore, it is actually CORRECT to say "I haven't any money" or "Haven't you a friend in the world?" instead of "I don't have any money" or "Don't you have a friend in the world".
As a side note, for those of you learning Japanese, it can help a lot when you try to decide how to phrase something in Japanese if you first understand just what the heck it is you're trying to express in English. Examine whether you're trying to express an action, existence, or possession. Same thing works well for Japanese trying to learn English. When you get ready to try to say something in English, if you're having trouble deciding how to go about it first decide which of those three classes what you want to express fits into.