Well, that's a fairly heinous definition of law enforcement working well as it also covers, say, fascist secret police. Society running smoothly should not be prioritized over society running ethically. This is the core of why you could consider police primarily protecting the property rights of rich people: a disrupted rich person is enormously inefficient in terms of capital use, but a disrupted poor person is just another burden on society without much effect on the economic health signals to which people refer.