Because our society is interdependent. In the case of housing, there has been a growing trend over the past decades of owning more than one home. In that case, to do that you undoubtedly affect people who just want to have a family and comfortable life socializing in their community because you force the price of houses to go up and house stock to become limited, which also forces people to rent ... And to make your investment work you push the rent higher because 'market forces' . . Aka you need to rent high enough to make a comfortable ROI/pay off your mortgage and upkeep with the rental income
This is only one example of what the hyper individualism mixed with capitalism for the sake capitalism creates in terms of disincentives for normal healthy communities