Even the libertarians among us aren't opposed to stop lights.
And, as my friend Zig Ziglar points out, they really should be called 'go' lights, because if you take them away, the traffic stops.
Self-organizing systems are terrific, but more often than not, systems don't self-organize. Try to get nine kids to agree on a batting order in Little League and it'll take a week. You could do it in ten seconds and they'll whine and then thank you for it.
Stop lights are essential in almost all marketplaces.
While individuals might moan about how they were treated, we all realize that without some sort of central allocation of scarce resources (like a piece of tarmac or a booth at a trade show), chaos ensues. And the chaos hurts everyone.
Too often, the central authority tries to exert too much of a tax, tries to profit from a market rather than make one. Smart traffic cops realize that facilitating an efficient transaction for enough people for long enough is almost certain to generate a terrific return.