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. It would be much better to pay reasonable compensation, and then encourage generosity. Don't get me wrong. Volunteerism is good.