The principle only holds if you are comparing switching between north-south or south-north. If you compare switching to not switching, it doesn't hold.
Let the switch cost something like 1 unit and the analysis on the Wikipedia example still holds - at the switch, drivers face a choice between a 41 minute route and a 45 minute route. Yes, this paradox is a property of the specifics of the network in question, but it may hold for real networks is the claim.
