Most people want to do things that they believe are worth doing for their own sake. Only those who gain property for the sake of gaining more property benefit from the current system, and they are given all the power because relations of ownership take precedence over all other concerns in the ideal conception of this system. So the ideology must claim that the system is for the benefit of all because the accumulation of profit/property is the motive of all, and that no one does anything useful for its own sake. To fail to do so invites questioning the primacy of property in determining the organization of society.