Walter isn't arguing for a greedy algorithm. He's giving an example of a local inefficiency and a mitigation. Lots of local inefficiencies add up to a global inefficiency. Illustrating a global inefficiency in itself isn't feasible in an anecdote. Thus I think your argument by assertion isn't possible to refute: you can bring up "local inefficiencies don't necessarily mean global inefficiencies" to dismiss all arguments that the current system is less than optimal.

Me, I've been stuck at traffic lights for 5 minutes at 2 in the morning, with no traffic whatsoever around. A very local algorithm would be highly preferable at that time of night, assuming usual (i.e. very little) traffic at that hour. It's an extreme example, yes: but there does exist a range of traffic patterns between the small hours of the morning and rush hour, and the same amount of global optimization effort is not applied to all hours, for obvious reasons. Something that could analyse the traffic using cameras and sensors and optimize wouldn't have to be paid extra to work late at night.