What is really special about Denial of Service attacks in cyberspace is the strikingly low cost to the attacker,

With the method the author outlined, it would actually require the same bandwidth from the attacker as the victim had in order to cause DoS. Hence it would cost the attacker the same as the cost to the victim for their internet connection bandwidths. The costs are actually similar to your truck analogy, sure you can clog up the road, but then you lose your truck in the process, so it still costs you something.