> There are many places where we know that a free market doesn’t properly function. Specifically, there are certain types of goods that end up priced wrong: those with externalities (positive or negative). So if all a company cares about is maximizing shareholder value over time they are drawn away from products with positive externalities (like a public park) towards those with negative externalities (like cars that pollute)

Sure, but that simply suggests that those externalities should be priced. Problem solved.