What, in your view, explains all these problems?

Trying to understand EA worldviews here. It seems to me like we think a lot about the "what" global health and animal welfare. I rarely hear people discuss why they think these issues exist, besides maybe a vague allusion to tight moral circles.

That being said, why do you personally believe that there are such big discrepancies in health across the world? Why do you think we have created a vast apparatus of animal torture? 

Feel free to answer similar questions for a cause area of your choice (although I'm honestly most curious about global health)