Here is an excerpt of my response to stimulate your appetite:
It might make more sense to argue that Chinese Martial Arts were created to promote the idea of universal responsibility. In a world with no aristocracy and no warrior class, it is the citizen-merchant-farmer who must be prepared to defend the nation, the family, and the internal social order. (Notice I did not include self-defense, which did not exist as an excuse for fighting in Chinese history.)
I absolutely love this question. If we look at all the individual and wildly diverse Chinese martial arts and all the individual and wildly diverse motivations people have for training in them--and try to work backwards to explain why they were created; it is a mighty tough task. What were the social milieus that inspired and supported the invention of Chinese martial arts? Do they exist in any form today?
I have commented in previous posts that there are quite a few books these days which assert that martial arts were created and preserved exclusively by people who had martial arts jobs. However; many martial arts creation stories talk about someone wandering out of the wilderness, or dreaming a dream, or finding a secret text. I find it hard to believe that these are just silly stories. It is more likely that they are summaries of a longer, more complex story. So in the next day or so I will take on the Taijiquan creation story.