Because the only way for the government to execute anything is to create a mindless, bureaucratic organization operating according to mindless, bureaucratic pro

Because the only way for the government to execute anything is to create a mindless, bureaucratic organization operating according to mindless, bureaucratic processes to do it. And the kind of person who will thrive in such an organization is not the kind of person who will be either good at helping others or motivated to do it. Only a private charity, answerable only to its owners and not to a fickle democratic process and a mindless bureaucracy, can exercise the kind of judgment required to find and keep the kind of people who are good at helping others and motivated to do it.