This change is predictable, as are many others, to the astute Taoist. In the end, walking the distance may have been more efficient. No answers to why questions. It is a philosophy when it is discussed as such, it is a religion when it's teachings are adopted as a way to live. I have a very technical answer for you.
Religion is the set of behavior manifest by people based on the things they believe to be true.
This set of beliefs may be conditioned or rationally founded but not superficial. For example, people frequently act in ways that are contrary to the things they profess - and this is because even though they profess a thing their belief in it may only be superficial. However, I prefer this definition to the popular one because it is far less vague. Philosophy is rather more detached - an intellectual exercise. There is nothing in Philosophy which dictates that a person act upon it.