I'll disagree as I think that's a misconception running through this thread. Breweries are businesses and they need to optimize, among a number of other factors, quality and turnaround time. Turnaround time is a major factor in the decisions they make and quality is not necessarily the biggest one. For homebrewers on the other hand it is (usually) all about quality. The Trappist breweries make good and often great beer, but that doesn't mean it's the best they could possibly make given infinite time and resources.
I agree that's the way most breweries operate. But I have to disagree about that in regards to the trappists (and possibly other abbey breweries). It even stated in the book that the head monk guy (who only oversees the monastery, but might not have any direct involvement in the brewery) has to approve whether or not they can produce more beer than they are. They limit how much they are allowed to produce because it's a monastery with a brewery, not a brewery with a monastery. Yes they're after some money, but they're not after the big bucks. They're not driven by capitalist greed like most other businesses out there. For the trappists, their pride comes from the quality of the beer, not the quantity.