While I have some sympathy with the point, I realized there was something important he'd missed, so I shipped a letter off to him:
The advantage to agriculture, and what I think is the reason that the hunter gatherers settled down, was that you get to make beer. Beer needs an abundance of grain, which you're not going to get bashing about the countryside. Then you have to hang around while it is fermenting, which means you start building more permanent structures. You need proper containers for the fermenting and storage, so you have to go invent clay pots and glass containers. Most beer is better cooled...so you need to develop deep cellars or refridgeration. This leads naturally to pubs and bars, and all of their support structure. A few more iterations, and voila, civilization.
It's all about the beer
This got the one line reply:
Damn. You have destroyed my entire argument....
That made my day. :-)