The U.S. has been disappointed in trying to raise funds for charities through the present system of mail, high-priced staff, and volunteers. People are not like the Charities presume. Volunteers won't work hard, and they become disillusioned and burned out. They are stingy. You are right.
People are stingy.
Put another way, Man , in distributing his money among the many alternatives, seeks to maximize his marginal utility . When he parts with a dollar, there is nothing that he has not purchased or donated to, that he has a greater desire. People are indeed stingy. Put another way, if they work real hard, whether working for a socialist manufacturer or working for a charity, they would like to be paid for it. They needed people who were cooperators - not competitors.