What are the reasons why of was made?

Please clarify your question. What do you mean by "of"?

Are you asking:

* Why was something specific made? (e.g., "Why was the Eiffel Tower made?" or "Why was the internet made?")

* Why was a particular concept or idea developed? (e.g., "Why was the theory of relativity developed?")

* Why was a particular word or phrase created? (e.g., "Why was the word 'of' created?")

Once you provide more context, I can give you a better answer.