“WHY ARE THEY DOING THAT?!!” Well, they have philosophies that were built up over the course of eons that inform their local customs and politics and they live lives marinated in ideas you have never even pondered (much less experienced), and so their lives and their reasons are complex and difficult for anyone with brains in different skulls to understand.
This is true for all of us.
What we see is only the end-point—the now. We rarely see the many contributing factors or imagine that motivations of others could differ from our own.