If you're looking from a point of view of a web designer, sure, it's a lot easier and faster to create dynamic sites. And the tools have become more sophisticated all the time to make it more user-friendly and attractive to search engines.
But from a retailer's point of view, I think you guys are missing an important element, and that is the organic "feel" of the site.
The reason some retail stores do well and other do not is the "feel" of the store when you walk in. It's an art, not a science. Dynamic sites have a tendancy to have a clinical feel to them, almost manufactured (which they are), whereas static sites are more likely to exude a more living feel to them, even while retaining the basic "look and feel" of the rest of the site.
It's the little things that make a difference that are hard to produce with a dynamic formula.
As for large sites, some of my sites have over 300 pages -- all static. Yeah, it took a while, but once done, it was worth it from the customer's point of view.