Hoarding wealth is like any other form.of hoarding. Its a mental illness.

If there was a monkey in the jungle somewhere who had stockpiled enough bananas, through killing other monkeys or other exploitative means, to last a thousand lifetimes and refused to share any, we would study that monkey like crazy to figure out WTF is going on there.

When a person does it and someone points out that its fucked, we say that the person pointing it out is just jealous, and if they only worked harder, they too could be sitting on a banana fortune.