The economic idea of self-interest as the driving motivator of economic (and other) behavior is as widely accepted by economists as it is criticized by others. The critics, generally, object to the assumption that widespread and/or persistent human behavior can be explained by a generalized calculus of utility-maximizing behavior, to quote George Stigler and Gary Becker. Is not that selfishness? And is not selfishness immoral? And do not people, at least sometimes, act morally? Furthermore, should not they be encouraged to act altruistically instead of only thinking of their own interests?
In reality, context complicates such moralisms.