Cousin marriage (ફુઈ વાંહે ભત્રીજી) practice in our culture: Why did it start, and how is it viewed today?

What are the historical origins of cousin marriage practices in certain communities?

Just a quick note: the question asked above in the post above is my own and is not intended to offend or target anyone. My goal is simply to spark a conversation. If it was interpreted differently, I sincerely apologize.