This doesn't make sense to me and are not mutually exclusive. Amazon Inc. employes and pays people, where as a CEO he has certain responsibilities and duties,

This doesn't make sense to me and are not mutually exclusive. Amazon Inc. employes and pays people, where as a CEO he has certain responsibilities and duties, and is answerable to the board, which he needs to take into account. Here he's donating his personal money which does not require any such considerations and he can do what he wants.