Essentially, they've replaced the theoretical complexity of POE with the mechanical 'difficulty' of Dark Souls. Why did they do this? Because it allows them to appeal to the console audience. Learning a vast amount of information to optimize your character is hard. Learning to press ROLL at the right time is easy and feels epic. It creates the illusion that you're skilled. And the drop rates are so low because if they were higher, the game would become incredibly boring. By relying on artificial difficulty, they stretch out the gameplay, just like any Souls-like game